Jennifer Kowalski - Academia.edu (original) (raw)

Papers by Jennifer Kowalski

bioRxiv (Cold Spring Harbor Laboratory), Feb 12, 2024

The FASEB Journal, Apr 1, 2016

Participation in undergraduate research increases student interest and retention in science, recr... more Participation in undergraduate research increases student interest and retention in science, recruits students into scientific careers, and instills greater self-confidence in research skills. With...

microPublication Biology, 2018

Figure 1. oxi-1 and fshr-1 loss-of-function mutants exhibit reduced body bending rates compared t... more Figure 1. oxi-1 and fshr-1 loss-of-function mutants exhibit reduced body bending rates compared to wild type N2 worms under both normal and oxidative stress conditions. (A) oxi-1(ok1217) and fshr-1(ok778) mutants showed 11.0% (p < 0.0001) and 11.2 % (p < 0.00001) reductions in body bends, respectively, compared to N2 animals when tested in the absence of prior oxidative stress. Worms were young adult aged and grown at 20 o C (n = 33 N2, 33 oxi-1, and 44 fshr-1). (B) oxi-1(ok1217) and fshr-1(ok778) mutants exposed to oxidative stress both had further reduced body bending rates compared to N2 worms with differences of 19.2% (p < 0.001) and 29.2% (p < 0.0000001), respectively. Worms were exposed to 5 mM paraquat for 48 hours beginning at the L3/L4 stage prior to being assayed for body bends as young adults (n = 28 N2, 29 oxi-1, and 22 fshr-1).

The American Biology Teacher, 2017

The use of primary scientific inquiry and experimentation to develop students’ understanding of m... more The use of primary scientific inquiry and experimentation to develop students’ understanding of methodologies used by scientists and the nature of science is a key component of the Next-Generation Science Standards (NGSS). Introduction to inquiry-based experimentation also has been shown to improve students’ attitudes and interest in science. However, implementing scientific inquiry activities that include experimental design and data analysis in a classroom of middle or high school students can be daunting for teachers with limited experimental experience. Here, we present a four- to five-day, inquiry-based laboratory activity designed to teach students about the scientific process and excite them about scientific discovery while providing opportunities for interactions of both teachers and students with scientists in the field. Within this laboratory module, students make observations and develop their own research questions, then design, execute, analyze, and present the results ...

PeerJ, 2016

The regulation of fundamental aspects of neurobiological function has been linked to the ubiquiti... more The regulation of fundamental aspects of neurobiological function has been linked to the ubiquitin signaling system (USS), which regulates the degradation and activity of proteins and is catalyzed by E1, E2, and E3 enzymes. The Anaphase-Promoting Complex (APC) is a multi-subunit E3 ubiquitin ligase that controls diverse developmental and signaling processes in post-mitotic neurons; however, potential roles for the APC in sensory function have yet to be explored. In this study, we examined the effect of the APC ubiquitin ligase on chemosensation in Caenorhabditis elegans by testing chemotaxis to the volatile odorants, diacetyl, pyrazine, and isoamyl alcohol, to which wild-type worms are attracted. Animals with loss of function mutations in either of two alleles (g48 and ye143) of the gene encoding the APC subunit EMB-27 APC6 showed increased chemotaxis towards diacetyl and pyrazine, odorants sensed by AWA neurons, but exhibited normal chemotaxis to isoamyl alcohol, which is sensed by...

J Immunology, 2006

Endothelial cell ICAM-1 interacts with leukocyte beta2 integrins to mediate adhesion and transmit... more Endothelial cell ICAM-1 interacts with leukocyte beta2 integrins to mediate adhesion and transmit outside-in signals that facilitate leukocyte transmigration. ICAM-1 redistribution and clustering appear necessary for leukocyte transmigration, but the mechanisms controlling ICAM-1 redistribution and clustering have not been identified. We recently reported that Src kinase phosphorylation of endothelial cortactin regulates polymorphonuclear cell (PMN) transmigration. In this study, we tested the hypotheses that the Src family kinase-cortactin pathway mediates association of ICAM-1 with the actin cytoskeleton and that this association is required for ICAM-1 clustering and leukocyte transmigration. Cross-linking ICAM-1 induced cytoskeletal remodeling and a decrease in ICAM-1 lateral mobility, as assessed by fluorescence recovery after photobleaching. Cytoskeletal remodeling after ICAM-1 cross-linking was reduced by knockdown of cortactin by small interfering RNA, by expression of a cortactin mutant deficient in Src phosphorylation sites (cortactin3F), and by the Src kinase inhibitor PP2. Pretreatment of cytokine-activated human endothelial monolayers with cortactin small interfering RNA significantly decreased both actin and ICAM-1 clustering around adherent PMN and the formation of actin-ICAM-1 clusters required for PMN transmigration. Our data suggest a model in which tyrosine phosphorylation of cortactin dynamically links ICAM-1 to the actin cytoskeleton, enabling ICAM-1 to form clusters and facilitate leukocyte transmigration. Note: Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information will be required for access. Users not affiliated with Butler University should contact their local librarian for assistance in locating a copy of this article

Journal of Neuroscience, 2011

Ubiquitin-mediated endocytosis and post-endocytic trafficking of glutamate receptors control thei... more Ubiquitin-mediated endocytosis and post-endocytic trafficking of glutamate receptors control their synaptic abundance and are implicated in modulating synaptic strength. Ubiquitination is a reversible modification, but the identities and specific functions of deubiquitinating enzymes in the nervous system are lacking. Here, we show that the deubiquitinating enzyme ubiquitin-specific protease-46 (USP-46) regulates the abundance of the glutamate receptor GLR-1 in the ventral nerve cord of Caenorhabditis elegans. Mutants lacking usp-46 have decreased GLR-1 in the ventral nerve cord and corresponding defects in GLR-1-dependent behaviors. The amount of ubiquitinated GLR-1 is increased in usp-46 mutants. Mutations that block GLR-1 ubiquitination or receptor degradation in the multivesicular body/lysosome prevent the decrease in GLR-1 observed in usp-46 mutants. These data support a model in which USP-46 promotes GLR-1 abundance at synapses by deubiquitinating GLR-1 and preventing its degradation in the lysosome. This work suggests that the balance between the addition and removal of ubiquitin is important for glutamate receptor trafficking.

Molecular Biology of the Cell, 2012

The transport of glutamate receptors from the cell body to synapses is essential during neuronal ... more The transport of glutamate receptors from the cell body to synapses is essential during neuronal development and may contribute to the regulation of synaptic strength in the mature nervous system. We previously showed that cyclin-dependent kinase-5 (CDK-5) positively regulates the abundance of GLR-1 glutamate receptors at synapses in the ventral nerve cord (VNC) of Caenorhabditis elegans. Here we identify a kinesin-3 family motor klp-4/KIF13 in a cdk-5 suppressor screen for genes that regulate GLR-1 trafficking. klp-4 mutants have decreased abundance of GLR-1 in the VNC. Genetic analysis of klp-4 and the clathrin adaptin unc-11/AP180 suggests that klp-4 functions before endocytosis in the ventral cord. Time-lapse microscopy indicates that klp-4 mutants exhibit decreased anterograde flux of GLR-1. Genetic analysis of cdk-5 and klp-4 suggests that they function in the same pathway to regulate GLR-1 in the VNC. Interestingly, GLR-1 accumulates in cell bodies of cdk-5 but not klp-4 muta...

Molecular and Cellular Neuroscience, 2014

Regulation of both excitatory and inhibitory synaptic transmission is critical for proper nervous... more Regulation of both excitatory and inhibitory synaptic transmission is critical for proper nervous system function. Aberrant synaptic signaling, including altered excitatory to inhibitory balance, is observed in numerous neurological diseases. The ubiquitin enzyme system controls the abundance of many synaptic proteins and thus plays a key role in regulating synaptic transmission. The Anaphase-Promoting Complex (APC) is a multi-subunit ubiquitin ligase that was originally discovered as a key regulator of protein turnover during the cell cycle. More recently, the APC has been shown to function in postmitotic neurons, where it regulates diverse processes such as synapse development and synaptic transmission at glutamatergic synapses. Here we report that the APC regulates synaptic GABA signaling by acting in motor neurons to control the balance of excitatory (acetylcholine) to inhibitory (GABA) transmission at the Caenorhabditis elegans neuromuscular junction (NMJ). Loss-of-function mutants in multiple APC subunits have increased muscle excitation at the NMJ; this phenotype is rescued by expression of the missing subunit in GABA neurons. Quantitative imaging and electrophysiological analyses indicate that APC mutants have decreased GABA release but normal cholinergic transmission. Consistent with this, APC mutants exhibit convulsions in a seizure assay sensitive to reductions in GABA signaling. Previous studies in other systems showed that the APC can negatively regulate the levels of the active zone protein SYD-2 Liprin-α. Similarly, we found that SYD-2 accumulates in APC mutants at GABAergic presynaptic sites. Finally, we found that the APC subunit EMB-27 CDC16 can localize to presynapses in GABA neurons. Together, our data suggest a model in which the APC acts at GABAergic presynapses to promote GABA release and inhibit muscle excitation. These findings are the first evidence that the APC regulates transmission at inhibitory synapses and have implications for understanding nervous system pathologies, such as epilepsy, that are characterized by misregulated GABA signaling.

Neural Plasticity, 2012

Posttranslational modification of proteins by ubiquitin has emerged as a critical regulator of sy... more Posttranslational modification of proteins by ubiquitin has emerged as a critical regulator of synapse development and function. Ubiquitination is a reversible modification mediated by the concerted action of a large number of specific ubiquitin ligases and ubiquitin proteases, called deubiquitinating enzymes (DUBs). The balance of activity of these enzymes determines the localization, function, and stability of target proteins. While some DUBs counter the action of specific ubiquitin ligases by removing ubiquitin and editing ubiquitin chains, other DUBs function more generally to maintain the cellular pool of free ubiquitin monomers. The importance of DUB function at the synapse is underscored by the association of specific mutations in DUB genes with several neurological disorders. Over the last decade, although much research has led to the identification and characterization of many ubiquitin ligases at the synapse, our knowledge of the relevant DUBs that act at the synapse has l...

Chembiochem : a European journal of chemical biology, Sep 12, 2017

Protein expression and localization are often studied in vivo by tagging molecules with green flu... more Protein expression and localization are often studied in vivo by tagging molecules with green fluorescent protein (GFP), yet subtle changes in protein levels are not easily detected. To develop a sensitive in vivo method to amplify fluorescence signals and allow cell-specific quantification of protein abundance changes, we sought to apply an enzyme-activated cellular fluorescence system in vivo by delivering ester-masked fluorophores to Caenorhabditis elegans neurons expressing porcine liver esterase (PLE). To aid uptake into sensory neuron membranes, we synthesized two novel fluorogenic hydrolase substrates with long hydrocarbon tails. Recombinant PLE activated these fluorophores in vitro. In vivo activation occurred in sensory neurons, along with potent activation in intestinal lysosomes quantifiable by imaging and microplate and partially attributable to gut esterase 1 (GES-1) activity. These data demonstrate the promise of biorthogonal hydrolases and their fluorogenic substrates...

CBE life sciences education, 2016

Classroom undergraduate research experiences (CUREs) provide students access to the measurable be... more Classroom undergraduate research experiences (CUREs) provide students access to the measurable benefits of undergraduate research experiences (UREs). Herein, we describe the implementation and assessment of a novel model for cohesive CUREs focused on central research themes involving faculty research collaboration across departments. Specifically, we implemented three collaborative CUREs spanning chemical biology, biochemistry, and neurobiology that incorporated faculty members' research interests and revolved around the central theme of visualizing biological processes like Mycobacterium tuberculosis enzyme activity and neural signaling using fluorescent molecules. Each CURE laboratory involved multiple experimental phases and culminated in novel, open-ended, and reiterative student-driven research projects. Course assessments showed CURE participation increased students' experimental design skills, attitudes and confidence about research, perceived understanding of the sci...

The Journal of Immunology, 2006

Endothelial cell ICAM-1 interacts with leukocyte ␤ 2 integrins to mediate adhesion and transmit o... more Endothelial cell ICAM-1 interacts with leukocyte ␤ 2 integrins to mediate adhesion and transmit outside-in signals that facilitate leukocyte transmigration. ICAM-1 redistribution and clustering appear necessary for leukocyte transmigration, but the mechanisms controlling ICAM-1 redistribution and clustering have not been identified. We recently reported that Src kinase phosphorylation of endothelial cortactin regulates polymorphonuclear cell (PMN) transmigration. In this study, we tested the hypotheses that the Src family kinase-cortactin pathway mediates association of ICAM-1 with the actin cytoskeleton and that this association is required for ICAM-1 clustering and leukocyte transmigration. Cross-linking ICAM-1 induced cytoskeletal remodeling and a decrease in ICAM-1 lateral mobility, as assessed by fluorescence recovery after photobleaching. Cytoskeletal remodeling after ICAM-1 cross-linking was reduced by knockdown of cortactin by small interfering RNA, by expression of a cortactin mutant deficient in Src phosphorylation sites (cortactin3F), and by the Src kinase inhibitor PP2. Pretreatment of cytokine-activated human endothelial monolayers with cortactin small interfering RNA significantly decreased both actin and ICAM-1 clustering around adherent PMN and the formation of actin-ICAM-1 clusters required for PMN transmigration. Our data suggest a model in which tyrosine phosphorylation of cortactin dynamically links ICAM-1 to the actin cytoskeleton, enabling ICAM-1 to form clusters and facilitate leukocyte transmigration.

Journal of Cell Science, 2004

Cortactin is an actin-associated scaffolding protein that regulates cell migration. Amplification... more Cortactin is an actin-associated scaffolding protein that regulates cell migration. Amplification of the human gene, EMS1, has been detected in breast, head and neck tumors, where it correlates with increased invasiveness. Cortactin can regulate actin dynamics directly via its N-terminal half, which can bind and activate the Arp2/3 complex. The C-terminal portion of cortactin, however, is thought to have limited function in its regulation of the actin polymerization machinery. In this report, we identify a role for the cortactin C-terminus in regulating cell migration and, more specifically, actin dynamics. Overexpression of either full-length cortactin or cortactin C-terminus is sufficient to enhance migration of mammary epithelial cells. In vitro, cortactin binds to and activates, via its SH3 domain, a regulator of the Arp2/3 complex, neural Wiskott Aldrich Syndrome protein (N-WASP). This in vitro activation of N-WASP is likely to be important in vivo, as cortactin-enhanced migrat...

Circulation Research, 2006

The underlying mechanisms that regulate leukocyte transendothelial migration through the vascular... more The underlying mechanisms that regulate leukocyte transendothelial migration through the vascular endothelium remain unclear. Cortactin is a substrate of Src tyrosine kinases and a regulator of cytoskeletal dynamics. Previous studies demonstrated a role for Src phosphorylation of cortactin in clustering of E-selectin and intercellular cell adhesion molecule-1 around adherent leukocytes. In the current study, we used an in vitro flow model to investigate the role of Src-induced cortactin phosphorylation in endothelium during polymorphonuclear leukocyte (PMN) transmigration through human umbilical vein endothelium (HUVEC) monolayers preactivated with tumor necrosis factor-α. Inhibition of Src in HUVEC using Src kinase inhibitors PP2 and SU6656 reduced PMN transmigration by 45±8% and 36±6%, respectively. Live cell imaging of green fluorescent protein–tagged cortactin in HUVEC revealed redistribution of cortactin in the region surrounding transmigrating PMN. Knockdown of cortactin in HU...

Cell, 2000

It is a reversible genetic alteration that is Baylor College of Medicine common in situations in ... more It is a reversible genetic alteration that is Baylor College of Medicine common in situations in which extra quantities of a gene One Baylor Plaza product bestow a growth advantage upon cells (re-Houston, Texas 77030 viewed by Stark and Wahl, 1984; Windle and Wahl, 1992). Amplification is evolutionarily and developmentally important. It is a more flexible, less risky genome alteration Summary than point mutation. First, it is reversible-homologous recombination between DNA repeats can reduce them Adaptive mutation is an induced response to environback to a single copy (see e.g., Tlsty et al., 1984). Secmental stress in which mutation rates rise, producing ond, amplification can allow elaboration of new gene permanent genetic changes that can adapt cells to functions without loss of potentially important old ones, stress. This contrasts with neo-Darwinian views of gebecause the original is preserved in an unaltered copy netic change rates blind to environmental conditions. (Ono, 1970). Finally, like point mutation, amplification is DNA amplification is a flexible, reversible genomic a major route to oncogenesis and cancer progression, change that has long been postulated to be adaptive. and it is often a higher frequency event than point muta-We report the discovery of adaptive amplification at tion (Brodeur and Hogarty, 1998). Because of the rethe lac operon in Escherichia coli. Additionally, we find markable potential for genetic adaptability that amplifithat adaptive amplification is separate from, and does cation can confer, it has long been postulated that not lead to, adaptive point mutation. This contradicts amplification might be an adaptive response to selective a prevailing alternative hypothesis whereby adaptive conditions (e.g., Echols, 1981; Tlsty et al., 1984; Whorimutation is normal mutability in amplified DNA. Inskey et al., 1987). In the sole previous investigation of stead, adaptive mutation and amplification are parallel this possibility, amplification was found not to be inducroutes of inducible genetic instability allowing rapid ible in a study of rat liver cells under a drug selection evolution under stress, and escape from growth inhi-(Tlsty et al., 1989). To our knowledge, no other rigorous bition. study has been made. We shall report that amplification of the lac operon in Escherichia coli is adaptive, arising * To whom correspondence should be addressed (e-mail: hastings@ sequences mimic lac reversions in cells lacking postrepbcm.tmc.edu).

Neuroscience Insights, 2020

Regulation of excitatory to inhibitory signaling balance is essential to nervous system health an... more Regulation of excitatory to inhibitory signaling balance is essential to nervous system health and is maintained by numerous enzyme systems that modulate the activity, localization, and abundance of synaptic proteins. SUMOylation is a key post-translational regulator of protein function in diverse cells, including neurons. There, its role in regulating synaptic transmission through pre- and postsynaptic effects has been shown primarily at glutamatergic central nervous system synapses, where the sole SUMO-conjugating enzyme Ubc9 is a critical player. However, whether Ubc9 functions globally at other synapses, including inhibitory synapses, has not been explored. Here, we investigated the role of UBC-9 and the SUMOylation pathway in controlling the balance of excitatory cholinergic and inhibitory GABAergic signaling required for muscle contraction in Caenorhabditis elegans. We found inhibition or overexpression of UBC-9 in neurons modestly increased muscle excitation. Similar and even...