Janos Demeter - Academia.edu (original) (raw)
Papers by Janos Demeter
3: Multimodal Molecular Analysis Reveals Divergent Trajectories Of Wound Regeneration Versus Fibrosis
Plastic and Reconstructive Surgery - Global Open, 2021
Purpose: Scarring in the mouse dorsal dermis is mediated by pro-fibrotic, Engrailed-1 lineage-pos... more Purpose: Scarring in the mouse dorsal dermis is mediated by pro-fibrotic, Engrailed-1 lineage-positive fibroblasts (EPFs). We recently showed that mechanotransduction blockade (YAP inhibition, using the drug verteporfin), results in complete wound regeneration, with full recovery of normal dermal appendages (hair follicles, glands), extracellular matrix (ECM) architecture, and tensile strength. This regenerative outcome following verteporfin treatment is mediated by Engrailed-1 lineage-negative fibroblasts (ENFs). The complex milieu of cell types and molecular signals involved in wound repair makes it difficult to study using any single data modality. Thus, we sought to use a holistic approach, incorporating multiple high-throughput, high-dimensional analyses, to define the divergent molecular events distinguishing typical scarring healing from verteporfin-induced wound regeneration. Methods: C57BL/6J mice underwent dorsal splinted excisional wounding per standard protocol. Wounds were treated with local injection of either verteporfin or vehicle control (PBS) on POD 0. We harvested unwounded skin and wounds at POD 2, 7, 14, and 30 (n=5 mice/timepoint and treatment) and subjected wound cells to three analyses: single-cell RNA-sequencing (scRNA-seq, using 10X Genomics Chromium); timsTOF, a recently-developed, high-throughput proteomic sequencing platform; and a novel machine learning algorithm for quantitatively comparing ECM ultrastructure. Results: Pseudotime analysis (Monocle3) of pooled scRNA-seq data revealed that fibroblasts followed two distinct transcriptional trajectories, one characterized by mechanical activation (En-1 lineage-positive, “fibrotic” trajectory) and the other characterized by developmental and regenerative pathways (En-1 lineage-negative; Rspo1, Dkk2/3, Trps1). Cross-platform data integration confirmed that fibroblasts in the fibrotic trajectory correlated with myofibroblast proteomic signatures (Col1a1/2, Fn1, etc.) and fibrotic/scar ECM features. In contrast, fibroblasts in the regenerative trajectory negatively correlated with myofibroblast markers and were associated with a “basket-weave” ECM pattern quantitatively indistinguishable from that of unwounded skin. Our integrated dataset suggested an important role for Wnt pathway proteins in ENF-mediated skin regeneration, so we compared POD 14 scars and regenerated wounds by multiplexed in situ hybridization (RNAScope) for Rspo1 (Wnt agonist), Trps1 (master hair follicle regulator), Ank1 (YAP target gene), and Dpp4 (EPF marker). Quantification of RNA granules across thousands of cells using a custom image analysis pipeline revealed that ENF-mediated healing (low Dpp4) in YAP-inhibited (low Ank1) wounds yielded regeneration of functional hair follicles through Wnt-mediated pathway activation (high Rpos1, Trps1). These data suggest that YAP inhibition unlocks wound regeneration via Wnt-active, En-1 lineage-negative fibroblasts. Conclusion: By studying regenerating (verteporfin-treated) versus scarring wounds across multiple healing timepoints and high-dimensional data modalities, we were able to profile fibrotic versus regenerative healing at unprecedented depth. Our integrated analysis revealed that dermal fibroblasts in these two wound settings exhibit distinct molecular trajectories defined by divergent transcriptomic, proteomic, and ultrastructural properties. Further, we found that wound regeneration in the context of verteporfin treatment is associated with suppression of mechanical signaling and activation of key Wnt pathway members including Trps1 (a gene with known hair follicle developmental roles). These results could have important implications for both the fundamental study of wound healing and potential anti-scarring therapeutic avenues
Intrinsic androgen-dependent gene expression patterns revealed by comparison of genital fibroblasts from normal males and individuals with complete and partial androgen insensitivity syndrome-0
<b>Copyright information:</b>Taken from "Intrinsic androgen-dependent gene expre... more <b>Copyright information:</b>Taken from "Intrinsic androgen-dependent gene expression patterns revealed by comparison of genital fibroblasts from normal males and individuals with complete and partial androgen insensitivity syndrome"http://www.biomedcentral.com/1471-2164/8/376BMC Genomics 2007;8():376-376.Published online 18 Oct 2007PMCID:PMC2212662.ual transcripts are grouped by hierarchical cluster analysis and are displayed in rows while experiments are represented in columns. Expression values per gene are centered by the mean logred/green normalized ratio. Increasing red intensity corresponds to higher relative transcript levels compared to the mean expression level across all 15 array experiments. Increasing green intensity corresponds to relatively decreased transcript levels compared to the mean. On the right side, examples of individual genes (gene symbols according to S.O.U.R.C.E. []) discussed in the paper or falling into the biological processes and cellular pathways detected by PANTHER are displayed. Detailed data on figure 1 is available in additional files , , , .
GeneXplorer: an interactive web application for microarray data visualization and analysis-2
<b>Copyright information:</b>Taken from "GeneXplorer: an interactive web applica... more <b>Copyright information:</b>Taken from "GeneXplorer: an interactive web application for microarray data visualization and analysis"BMC Bioinformatics 2004;5():141-141.Published online 1 Oct 2004PMCID:PMC523853.Copyright © 2004 Rees et al; licensee BioMed Central Ltd.oom frame, the gene annotations table may contain an unlimited number of graphics and hyperlinks regarding the genes. These are configurable via a server-side stylesheet to accommodate different organism annotation. Clicking on these hyperlinks can take the user to e.g. SOURCE – on online collection of information about mammalian genes/clones. c.) SEARCH result display in zoom window. The search tool in the tool frame allows searching the annotations by any or all of the fields by using either words or wildcard searches. The result is displayed in the zoom window. d.) GeneXplorer's gene correlation display. The genes with expression patterns similar to the gene of interest are presented in an ordered list. The length of the orange bar to the right of the expression data indicates the magnitude of the correlation value.
doi:10.1093/nar/gkn786 Implementation of GenePattern within the Stanford Microarray Database
Hundreds of researchers across the world use the Stanford Microarray Database (SMD;
This article cites 52 articles, 27 of which can be accessed free
Author response: Proteomic analysis of young and old mouse hematopoietic stem cells and their progenitors reveals post-transcriptional regulation in stem cells
eLife, 2020
Abstract B25: Combined proteomic and genetic interaction mapping reveals new Ras pathway effectors and regulators
SSRN Electronic Journal, 2021
Anti-PD-1 immunotherapies have transformed cancer treatment, yet the determinants of clinical res... more Anti-PD-1 immunotherapies have transformed cancer treatment, yet the determinants of clinical response are largely unknown. We performed CODEX multiplexed tissue imaging and RNA sequencing on 70 tumor regions from 14 advanced cutaneous T cell lymphoma (CTCL) patients enrolled in a clinical trial of pembrolizumab therapy. Clinical response was not associated with the frequency of tumor-infiltrating T cell subsets, but rather with striking differences in the spatial organization and functional immune state of the tumor microenvironment (TME). After treatment, pembrolizumab responders had a localized enrichment of tumor and CD4+ T cells, which coincided with immune activation and cytotoxic PD-1+ CD4+ T cells. In contrast, non-responders had a localized enrichment of Tregs pre- and post-treatment, consistent with a persistently immunosuppressed TME and exhausted PD-1+ CD4+ T cells. Integrating these findings by computing the physical distances between PD-1+ CD4+ T cells, tumor cells, an...
Structured elements drive extensive circular RNA translation
Molecular Cell, 2021
The human genome encodes tens of thousands circular RNAs (circRNAs) with mostly unknown functions... more The human genome encodes tens of thousands circular RNAs (circRNAs) with mostly unknown functions. Circular RNAs require internal ribosome entry sites (IRES) if they are to undergo translation without a 5' cap. Here, we develop a high-throughput screen to systematically discover RNA sequences that can direct circRNA translation in human cells. We identify more than 17,000 endogenous and synthetic sequences as candidate circRNA IRES. 18S rRNA complementarity and a structured RNA element positioned on the IRES are important for driving circRNA translation. Ribosome profiling and peptidomic analyses show extensive IRES-ribosome association, hundreds of circRNA-encoded proteins with tissue-specific distribution, and antigen presentation. We find that circFGFR1p, a protein encoded by circFGFR1 that is downregulated in cancer, functions as a negative regulator of FGFR1 oncoprotein to suppress cell growth during stress. Systematic identification of circRNA IRES elements may provide important links among circRNA regulation, biological function, and disease.
eLife, 2020
The balance of hematopoietic stem cell (HSC) self-renewal and differentiation is critical for a h... more The balance of hematopoietic stem cell (HSC) self-renewal and differentiation is critical for a healthy blood supply; imbalances underlie hematological diseases. The importance of HSCs and their progenitors have led to their extensive characterization at genomic and transcriptomic levels. However, the proteomics of hematopoiesis remains incompletely understood. Here we report a proteomics resource from mass spectrometry of mouse young adult and old adult mouse HSCs, multipotent progenitors and oligopotent progenitors; 12 cell types in total. We validated differential protein levels, including confirmation that Dnmt3a protein levels are undetected in young adult mouse HSCs until forced into cycle. Additionally, through integrating proteomics and RNA-sequencing datasets, we identified a subset of genes with apparent post-transcriptional repression in young adult mouse HSCs. In summary, we report proteomic coverage of young and old mouse HSCs and progenitors, with broader implications ...
Genes & Development, 2021
Multiple G protein-coupled receptors (GPCRs) are expressed in pancreatic islet cells, but the maj... more Multiple G protein-coupled receptors (GPCRs) are expressed in pancreatic islet cells, but the majority have unknown functions. We observed specific GPCRs localized to primary cilia, a prominent signaling organelle, in pancreatic α and β cells. Loss of cilia disrupts β-cell endocrine function, but the molecular drivers are unknown. Using functional expression, we identified multiple GPCRs localized to cilia in mouse and human islet α and β cells, including FFAR4, PTGER4, ADRB2, KISS1R, and P2RY14. Free fatty acid receptor 4 (FFAR4) and prostaglandin E receptor 4 (PTGER4) agonists stimulate ciliary cAMP signaling and promote glucagon and insulin secretion by α- and β-cell lines and by mouse and human islets. Transport of GPCRs to primary cilia requires TULP3, whose knockdown in primary human and mouse islets relocalized ciliary FFAR4 and PTGER4 and impaired regulated glucagon or insulin secretion, without affecting ciliary structure. Our findings provide index evidence that regulated ...
Cell Metabolism, 2021
Highlights d SARS-CoV-2 infects b cells in COVID-19 patients and human islets in vitro d SARS-CoV... more Highlights d SARS-CoV-2 infects b cells in COVID-19 patients and human islets in vitro d SARS-CoV-2 infection causes b cell death and reduced GSIS in vitro d Phosphoproteomics shows SARS-CoV-2 spike protein and virus induce apoptotic kinases d High neuropilin-1 levels support b cell selectivity, and inhibitors block infection
SummaryIn response to excess nutrients, white adipose tissue expands by both generating new adipo... more SummaryIn response to excess nutrients, white adipose tissue expands by both generating new adipocytes and by upregulating lipogenesis in existing adipocytes. Here, we performed a genome-wide functional genomics screen to identify regulators of adipogenesis in the mouse 3T3-L1 cell model. The pooled screening strategy utilized FACS to isolate populations based on lipid content by gating for fluorescence intensity of the lipophilic, green fluorescent BODIPY 493/503 dye. Additionally, this approach categorized if genes functioned during mitotic expansion or lipogenesis. Cellular mechanisms regulating the rates of protein translation and protein stability were found to be critical for adipogenesis and lipogenesis. These mechanisms were further supported by proteomic analyses, which demonstrated that many changes in protein abundance during 3T3-L1 adipogenesis were not driven by transcription. Within these themes, we illustrate that hypusination is critical for translating adipogenic in...
ABSTRACTARHGAP36 is a Rho GTPase-activating protein (GAP) family member that contributes to spina... more ABSTRACTARHGAP36 is a Rho GTPase-activating protein (GAP) family member that contributes to spinal cord development and tumorigenesis. This multidomain protein is composed of splicing-dependent N-terminal sequences, the GAP-like region, and a unique C-terminal domain, and an N-terminal arginine-rich region has been shown to suppress protein kinase A (PKA) and activate Gli transcription factors. To understand how these structural elements act in concert, we have mapped the ARHGAP36 structure-activity landscape with domain- and amino-acid-level resolution. ARHGAP36-mediated Gli activation can be repressed by N-terminal sequences that regulate subcellular ARHGAP36 localization and PKA targeting. The GAP-like and C-terminal domains counteract this autoinhibitory mechanism and promote ARHGAP36 trafficking to the plasma membrane and primary cilium, respectively. The GAP-like domain may also conditionally suppress the arginine-rich region, and it modulates ARHGAP36 binding to the prolyl ol...
Cell, 2019
Highlights d Preadipocytes, located along blood vessels, are ciliated in vitro and in vivo d Loss... more Highlights d Preadipocytes, located along blood vessels, are ciliated in vitro and in vivo d Loss of preadipocyte ciliation strongly impairs white adipose tissue expansion d Ciliary GPCRs are critical for adipogenesis, and FFAR4/ GPR120 localizes to cilia d u-3 fatty acids activate ciliary FFAR4 and trigger adipogenesis via ciliary cAMP
SUMMARYAntitumoral immunity requires organized, spatially nuanced interactions between components... more SUMMARYAntitumoral immunity requires organized, spatially nuanced interactions between components of the immune tumor microenvironment (iTME). Understanding this coordinated behavior in effective versus ineffective tumor control will advance immunotherapies. We optimized CO-Detection by indEXing (CODEX) for para ffin-em bedded tissue microarrays, enabling profiling of 140 tissue regions from 35 advanced-stage colorectal cancer (CRC) patients with 56 protein markers simultaneously. We identified nine conserved, distinct cellular neighborhoods (CNs)–a collection of components characteristic of the CRC iTME. Enrichment of PD-1+CD4+ T cells only within a granulocyte CN positively correlated with survival in a high-risk patient subset. Coupling of tumor and immune CNs, fragmentation of T cell and macrophage CNs, and disruption of inter-CN communication was associated with inferior outcomes. This study provides a framework for interrogating complex biological processes, such as antitumora...
Nature Communications, 2019
E2F transcription factors are central regulators of cell division and cell fate decisions. E2F4 o... more E2F transcription factors are central regulators of cell division and cell fate decisions. E2F4 often represents the predominant E2F activity in cells. E2F4 is a transcriptional repressor implicated in cell cycle arrest and whose repressive activity depends on its interaction with members of the RB family. Here we show that E2F4 is important for the proliferation and the survival of mouse embryonic stem cells. In these cells, E2F4 acts in part as a transcriptional activator that promotes the expression of cell cycle genes. This role for E2F4 is independent of the RB family. Furthermore, E2F4 functionally interacts with chromatin regulators associated with gene activation and we observed decreased histone acetylation at the promoters of cell cycle genes and E2F targets upon loss of E2F4 in RB family-mutant cells. Taken together, our findings uncover a non-canonical role for E2F4 that provide insights into the biology of rapidly dividing cells.
Developmental cell, Jul 14, 2017
Highly conserved intraflagellar transport (IFT) protein complexes direct both the assembly of pri... more Highly conserved intraflagellar transport (IFT) protein complexes direct both the assembly of primary cilia and the trafficking of signaling molecules. IFT complexes initially accumulate at the base of the cilium and periodically enter the cilium, suggesting an as-yet-unidentified mechanism that triggers ciliary entry of IFT complexes. Using affinity-purification and mass spectrometry of interactors of the centrosomal and ciliopathy protein, CEP19, we identify CEP350, FOP, and the RABL2B GTPase as proteins organizing the first known mechanism directing ciliary entry of IFT complexes. We discover that CEP19 is recruited to the ciliary base by the centriolar CEP350/FOP complex and then specifically captures GTP-bound RABL2B, which is activated via its intrinsic nucleotide exchange. Activated RABL2B then captures and releases its single effector, the intraflagellar transport B holocomplex, from the large pool of pre-docked IFT-B complexes, and thus initiates ciliary entry of IFT.
Database : the journal of biological databases and curation, 2016
The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/) is the authoritative communi... more The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/) is the authoritative community resource for the Saccharomyces cerevisiae reference genome sequence and its annotation. To provide a wider scope of genetic and phenotypic variation in yeast, the genome sequences and their corresponding annotations from 11 alternative S. cerevisiae reference strains have been integrated into SGD. Genomic and protein sequence information for genes from these strains are now available on the Sequence and Protein tab of the corresponding Locus Summary pages. We illustrate how these genome sequences can be utilized to aid our understanding of strain-specific functional and phenotypic differences.Database URL: www.yeastgenome.org.
3: Multimodal Molecular Analysis Reveals Divergent Trajectories Of Wound Regeneration Versus Fibrosis
Plastic and Reconstructive Surgery - Global Open, 2021
Purpose: Scarring in the mouse dorsal dermis is mediated by pro-fibrotic, Engrailed-1 lineage-pos... more Purpose: Scarring in the mouse dorsal dermis is mediated by pro-fibrotic, Engrailed-1 lineage-positive fibroblasts (EPFs). We recently showed that mechanotransduction blockade (YAP inhibition, using the drug verteporfin), results in complete wound regeneration, with full recovery of normal dermal appendages (hair follicles, glands), extracellular matrix (ECM) architecture, and tensile strength. This regenerative outcome following verteporfin treatment is mediated by Engrailed-1 lineage-negative fibroblasts (ENFs). The complex milieu of cell types and molecular signals involved in wound repair makes it difficult to study using any single data modality. Thus, we sought to use a holistic approach, incorporating multiple high-throughput, high-dimensional analyses, to define the divergent molecular events distinguishing typical scarring healing from verteporfin-induced wound regeneration. Methods: C57BL/6J mice underwent dorsal splinted excisional wounding per standard protocol. Wounds were treated with local injection of either verteporfin or vehicle control (PBS) on POD 0. We harvested unwounded skin and wounds at POD 2, 7, 14, and 30 (n=5 mice/timepoint and treatment) and subjected wound cells to three analyses: single-cell RNA-sequencing (scRNA-seq, using 10X Genomics Chromium); timsTOF, a recently-developed, high-throughput proteomic sequencing platform; and a novel machine learning algorithm for quantitatively comparing ECM ultrastructure. Results: Pseudotime analysis (Monocle3) of pooled scRNA-seq data revealed that fibroblasts followed two distinct transcriptional trajectories, one characterized by mechanical activation (En-1 lineage-positive, “fibrotic” trajectory) and the other characterized by developmental and regenerative pathways (En-1 lineage-negative; Rspo1, Dkk2/3, Trps1). Cross-platform data integration confirmed that fibroblasts in the fibrotic trajectory correlated with myofibroblast proteomic signatures (Col1a1/2, Fn1, etc.) and fibrotic/scar ECM features. In contrast, fibroblasts in the regenerative trajectory negatively correlated with myofibroblast markers and were associated with a “basket-weave” ECM pattern quantitatively indistinguishable from that of unwounded skin. Our integrated dataset suggested an important role for Wnt pathway proteins in ENF-mediated skin regeneration, so we compared POD 14 scars and regenerated wounds by multiplexed in situ hybridization (RNAScope) for Rspo1 (Wnt agonist), Trps1 (master hair follicle regulator), Ank1 (YAP target gene), and Dpp4 (EPF marker). Quantification of RNA granules across thousands of cells using a custom image analysis pipeline revealed that ENF-mediated healing (low Dpp4) in YAP-inhibited (low Ank1) wounds yielded regeneration of functional hair follicles through Wnt-mediated pathway activation (high Rpos1, Trps1). These data suggest that YAP inhibition unlocks wound regeneration via Wnt-active, En-1 lineage-negative fibroblasts. Conclusion: By studying regenerating (verteporfin-treated) versus scarring wounds across multiple healing timepoints and high-dimensional data modalities, we were able to profile fibrotic versus regenerative healing at unprecedented depth. Our integrated analysis revealed that dermal fibroblasts in these two wound settings exhibit distinct molecular trajectories defined by divergent transcriptomic, proteomic, and ultrastructural properties. Further, we found that wound regeneration in the context of verteporfin treatment is associated with suppression of mechanical signaling and activation of key Wnt pathway members including Trps1 (a gene with known hair follicle developmental roles). These results could have important implications for both the fundamental study of wound healing and potential anti-scarring therapeutic avenues
Intrinsic androgen-dependent gene expression patterns revealed by comparison of genital fibroblasts from normal males and individuals with complete and partial androgen insensitivity syndrome-0
<b>Copyright information:</b>Taken from "Intrinsic androgen-dependent gene expre... more <b>Copyright information:</b>Taken from "Intrinsic androgen-dependent gene expression patterns revealed by comparison of genital fibroblasts from normal males and individuals with complete and partial androgen insensitivity syndrome"http://www.biomedcentral.com/1471-2164/8/376BMC Genomics 2007;8():376-376.Published online 18 Oct 2007PMCID:PMC2212662.ual transcripts are grouped by hierarchical cluster analysis and are displayed in rows while experiments are represented in columns. Expression values per gene are centered by the mean logred/green normalized ratio. Increasing red intensity corresponds to higher relative transcript levels compared to the mean expression level across all 15 array experiments. Increasing green intensity corresponds to relatively decreased transcript levels compared to the mean. On the right side, examples of individual genes (gene symbols according to S.O.U.R.C.E. []) discussed in the paper or falling into the biological processes and cellular pathways detected by PANTHER are displayed. Detailed data on figure 1 is available in additional files , , , .
GeneXplorer: an interactive web application for microarray data visualization and analysis-2
<b>Copyright information:</b>Taken from "GeneXplorer: an interactive web applica... more <b>Copyright information:</b>Taken from "GeneXplorer: an interactive web application for microarray data visualization and analysis"BMC Bioinformatics 2004;5():141-141.Published online 1 Oct 2004PMCID:PMC523853.Copyright © 2004 Rees et al; licensee BioMed Central Ltd.oom frame, the gene annotations table may contain an unlimited number of graphics and hyperlinks regarding the genes. These are configurable via a server-side stylesheet to accommodate different organism annotation. Clicking on these hyperlinks can take the user to e.g. SOURCE – on online collection of information about mammalian genes/clones. c.) SEARCH result display in zoom window. The search tool in the tool frame allows searching the annotations by any or all of the fields by using either words or wildcard searches. The result is displayed in the zoom window. d.) GeneXplorer's gene correlation display. The genes with expression patterns similar to the gene of interest are presented in an ordered list. The length of the orange bar to the right of the expression data indicates the magnitude of the correlation value.
doi:10.1093/nar/gkn786 Implementation of GenePattern within the Stanford Microarray Database
Hundreds of researchers across the world use the Stanford Microarray Database (SMD;
This article cites 52 articles, 27 of which can be accessed free
Author response: Proteomic analysis of young and old mouse hematopoietic stem cells and their progenitors reveals post-transcriptional regulation in stem cells
eLife, 2020
Abstract B25: Combined proteomic and genetic interaction mapping reveals new Ras pathway effectors and regulators
SSRN Electronic Journal, 2021
Anti-PD-1 immunotherapies have transformed cancer treatment, yet the determinants of clinical res... more Anti-PD-1 immunotherapies have transformed cancer treatment, yet the determinants of clinical response are largely unknown. We performed CODEX multiplexed tissue imaging and RNA sequencing on 70 tumor regions from 14 advanced cutaneous T cell lymphoma (CTCL) patients enrolled in a clinical trial of pembrolizumab therapy. Clinical response was not associated with the frequency of tumor-infiltrating T cell subsets, but rather with striking differences in the spatial organization and functional immune state of the tumor microenvironment (TME). After treatment, pembrolizumab responders had a localized enrichment of tumor and CD4+ T cells, which coincided with immune activation and cytotoxic PD-1+ CD4+ T cells. In contrast, non-responders had a localized enrichment of Tregs pre- and post-treatment, consistent with a persistently immunosuppressed TME and exhausted PD-1+ CD4+ T cells. Integrating these findings by computing the physical distances between PD-1+ CD4+ T cells, tumor cells, an...
Structured elements drive extensive circular RNA translation
Molecular Cell, 2021
The human genome encodes tens of thousands circular RNAs (circRNAs) with mostly unknown functions... more The human genome encodes tens of thousands circular RNAs (circRNAs) with mostly unknown functions. Circular RNAs require internal ribosome entry sites (IRES) if they are to undergo translation without a 5' cap. Here, we develop a high-throughput screen to systematically discover RNA sequences that can direct circRNA translation in human cells. We identify more than 17,000 endogenous and synthetic sequences as candidate circRNA IRES. 18S rRNA complementarity and a structured RNA element positioned on the IRES are important for driving circRNA translation. Ribosome profiling and peptidomic analyses show extensive IRES-ribosome association, hundreds of circRNA-encoded proteins with tissue-specific distribution, and antigen presentation. We find that circFGFR1p, a protein encoded by circFGFR1 that is downregulated in cancer, functions as a negative regulator of FGFR1 oncoprotein to suppress cell growth during stress. Systematic identification of circRNA IRES elements may provide important links among circRNA regulation, biological function, and disease.
eLife, 2020
The balance of hematopoietic stem cell (HSC) self-renewal and differentiation is critical for a h... more The balance of hematopoietic stem cell (HSC) self-renewal and differentiation is critical for a healthy blood supply; imbalances underlie hematological diseases. The importance of HSCs and their progenitors have led to their extensive characterization at genomic and transcriptomic levels. However, the proteomics of hematopoiesis remains incompletely understood. Here we report a proteomics resource from mass spectrometry of mouse young adult and old adult mouse HSCs, multipotent progenitors and oligopotent progenitors; 12 cell types in total. We validated differential protein levels, including confirmation that Dnmt3a protein levels are undetected in young adult mouse HSCs until forced into cycle. Additionally, through integrating proteomics and RNA-sequencing datasets, we identified a subset of genes with apparent post-transcriptional repression in young adult mouse HSCs. In summary, we report proteomic coverage of young and old mouse HSCs and progenitors, with broader implications ...
Genes & Development, 2021
Multiple G protein-coupled receptors (GPCRs) are expressed in pancreatic islet cells, but the maj... more Multiple G protein-coupled receptors (GPCRs) are expressed in pancreatic islet cells, but the majority have unknown functions. We observed specific GPCRs localized to primary cilia, a prominent signaling organelle, in pancreatic α and β cells. Loss of cilia disrupts β-cell endocrine function, but the molecular drivers are unknown. Using functional expression, we identified multiple GPCRs localized to cilia in mouse and human islet α and β cells, including FFAR4, PTGER4, ADRB2, KISS1R, and P2RY14. Free fatty acid receptor 4 (FFAR4) and prostaglandin E receptor 4 (PTGER4) agonists stimulate ciliary cAMP signaling and promote glucagon and insulin secretion by α- and β-cell lines and by mouse and human islets. Transport of GPCRs to primary cilia requires TULP3, whose knockdown in primary human and mouse islets relocalized ciliary FFAR4 and PTGER4 and impaired regulated glucagon or insulin secretion, without affecting ciliary structure. Our findings provide index evidence that regulated ...
Cell Metabolism, 2021
Highlights d SARS-CoV-2 infects b cells in COVID-19 patients and human islets in vitro d SARS-CoV... more Highlights d SARS-CoV-2 infects b cells in COVID-19 patients and human islets in vitro d SARS-CoV-2 infection causes b cell death and reduced GSIS in vitro d Phosphoproteomics shows SARS-CoV-2 spike protein and virus induce apoptotic kinases d High neuropilin-1 levels support b cell selectivity, and inhibitors block infection
SummaryIn response to excess nutrients, white adipose tissue expands by both generating new adipo... more SummaryIn response to excess nutrients, white adipose tissue expands by both generating new adipocytes and by upregulating lipogenesis in existing adipocytes. Here, we performed a genome-wide functional genomics screen to identify regulators of adipogenesis in the mouse 3T3-L1 cell model. The pooled screening strategy utilized FACS to isolate populations based on lipid content by gating for fluorescence intensity of the lipophilic, green fluorescent BODIPY 493/503 dye. Additionally, this approach categorized if genes functioned during mitotic expansion or lipogenesis. Cellular mechanisms regulating the rates of protein translation and protein stability were found to be critical for adipogenesis and lipogenesis. These mechanisms were further supported by proteomic analyses, which demonstrated that many changes in protein abundance during 3T3-L1 adipogenesis were not driven by transcription. Within these themes, we illustrate that hypusination is critical for translating adipogenic in...
ABSTRACTARHGAP36 is a Rho GTPase-activating protein (GAP) family member that contributes to spina... more ABSTRACTARHGAP36 is a Rho GTPase-activating protein (GAP) family member that contributes to spinal cord development and tumorigenesis. This multidomain protein is composed of splicing-dependent N-terminal sequences, the GAP-like region, and a unique C-terminal domain, and an N-terminal arginine-rich region has been shown to suppress protein kinase A (PKA) and activate Gli transcription factors. To understand how these structural elements act in concert, we have mapped the ARHGAP36 structure-activity landscape with domain- and amino-acid-level resolution. ARHGAP36-mediated Gli activation can be repressed by N-terminal sequences that regulate subcellular ARHGAP36 localization and PKA targeting. The GAP-like and C-terminal domains counteract this autoinhibitory mechanism and promote ARHGAP36 trafficking to the plasma membrane and primary cilium, respectively. The GAP-like domain may also conditionally suppress the arginine-rich region, and it modulates ARHGAP36 binding to the prolyl ol...
Cell, 2019
Highlights d Preadipocytes, located along blood vessels, are ciliated in vitro and in vivo d Loss... more Highlights d Preadipocytes, located along blood vessels, are ciliated in vitro and in vivo d Loss of preadipocyte ciliation strongly impairs white adipose tissue expansion d Ciliary GPCRs are critical for adipogenesis, and FFAR4/ GPR120 localizes to cilia d u-3 fatty acids activate ciliary FFAR4 and trigger adipogenesis via ciliary cAMP
SUMMARYAntitumoral immunity requires organized, spatially nuanced interactions between components... more SUMMARYAntitumoral immunity requires organized, spatially nuanced interactions between components of the immune tumor microenvironment (iTME). Understanding this coordinated behavior in effective versus ineffective tumor control will advance immunotherapies. We optimized CO-Detection by indEXing (CODEX) for para ffin-em bedded tissue microarrays, enabling profiling of 140 tissue regions from 35 advanced-stage colorectal cancer (CRC) patients with 56 protein markers simultaneously. We identified nine conserved, distinct cellular neighborhoods (CNs)–a collection of components characteristic of the CRC iTME. Enrichment of PD-1+CD4+ T cells only within a granulocyte CN positively correlated with survival in a high-risk patient subset. Coupling of tumor and immune CNs, fragmentation of T cell and macrophage CNs, and disruption of inter-CN communication was associated with inferior outcomes. This study provides a framework for interrogating complex biological processes, such as antitumora...
Nature Communications, 2019
E2F transcription factors are central regulators of cell division and cell fate decisions. E2F4 o... more E2F transcription factors are central regulators of cell division and cell fate decisions. E2F4 often represents the predominant E2F activity in cells. E2F4 is a transcriptional repressor implicated in cell cycle arrest and whose repressive activity depends on its interaction with members of the RB family. Here we show that E2F4 is important for the proliferation and the survival of mouse embryonic stem cells. In these cells, E2F4 acts in part as a transcriptional activator that promotes the expression of cell cycle genes. This role for E2F4 is independent of the RB family. Furthermore, E2F4 functionally interacts with chromatin regulators associated with gene activation and we observed decreased histone acetylation at the promoters of cell cycle genes and E2F targets upon loss of E2F4 in RB family-mutant cells. Taken together, our findings uncover a non-canonical role for E2F4 that provide insights into the biology of rapidly dividing cells.
Developmental cell, Jul 14, 2017
Highly conserved intraflagellar transport (IFT) protein complexes direct both the assembly of pri... more Highly conserved intraflagellar transport (IFT) protein complexes direct both the assembly of primary cilia and the trafficking of signaling molecules. IFT complexes initially accumulate at the base of the cilium and periodically enter the cilium, suggesting an as-yet-unidentified mechanism that triggers ciliary entry of IFT complexes. Using affinity-purification and mass spectrometry of interactors of the centrosomal and ciliopathy protein, CEP19, we identify CEP350, FOP, and the RABL2B GTPase as proteins organizing the first known mechanism directing ciliary entry of IFT complexes. We discover that CEP19 is recruited to the ciliary base by the centriolar CEP350/FOP complex and then specifically captures GTP-bound RABL2B, which is activated via its intrinsic nucleotide exchange. Activated RABL2B then captures and releases its single effector, the intraflagellar transport B holocomplex, from the large pool of pre-docked IFT-B complexes, and thus initiates ciliary entry of IFT.
Database : the journal of biological databases and curation, 2016
The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/) is the authoritative communi... more The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/) is the authoritative community resource for the Saccharomyces cerevisiae reference genome sequence and its annotation. To provide a wider scope of genetic and phenotypic variation in yeast, the genome sequences and their corresponding annotations from 11 alternative S. cerevisiae reference strains have been integrated into SGD. Genomic and protein sequence information for genes from these strains are now available on the Sequence and Protein tab of the corresponding Locus Summary pages. We illustrate how these genome sequences can be utilized to aid our understanding of strain-specific functional and phenotypic differences.Database URL: www.yeastgenome.org.