Signals, pathways and splicing regulation (original) (raw)

Defective control of pre–messenger RNA splicing in human disease

Journal of Cell Biology, 2016

Examples of associations between human disease and defects in pre–messenger RNA splicing/alternative splicing are accumulating. Although many alterations are caused by mutations in splicing signals or regulatory sequence elements, recent studies have noted the disruptive impact of mutated generic spliceosome components and splicing regulatory proteins. This review highlights recent progress in our understanding of how the altered splicing function of RNA-binding proteins contributes to myelodysplastic syndromes, cancer, and neuropathologies.

Rapid-Response Splicing Reporter Screens Identify Differential Regulators of Constitutive and Alternative Splicing

Molecular and Cellular Biology, 2010

Bioactive compounds have been invaluable for dissecting the mechanisms, regulation, and functions of cellular processes. However, very few such reagents have been described for pre-mRNA splicing. To facilitate their systematic discovery, we developed a high-throughput cell-based assay that measures pre-mRNA splicing by utilizing a quantitative reporter system with advantageous features. The reporter, consisting of a destabilized, intron-containing luciferase expressed from a short-lived mRNA, allows rapid screens (<4 h), thereby obviating the potential toxicity of splicing inhibitors. We describe three inhibitors (out of >23,000 screened), all pharmacologically active: clotrimazole, flunarizine, and chlorhexidine. Interestingly, none was a general splicing inhibitor. Rather, each caused distinct splicing changes of numerous genes. We further discovered the target of action of chlorhexidine and show that it is a selective inhibitor of specific Cdc2-like kinases (Clks) that phos...

Phosphorylation-mediated regulation of alternative splicing in cancer

International journal of cell biology, 2013

Alternative splicing (AS) is one of the key processes involved in the regulation of gene expression in eukaryotic cells. AS catalyzes the removal of intronic sequences and the joining of selected exons, thus ensuring the correct processing of the primary transcript into the mature mRNA. The combinatorial nature of AS allows a great expansion of the genome coding potential, as multiple splice-variants encoding for different proteins may arise from a single gene. Splicing is mediated by a large macromolecular complex, the spliceosome, whose activity needs a fine regulation exerted by cis-acting RNA sequence elements and trans-acting RNA binding proteins (RBP). The activity of both core spliceosomal components and accessory splicing factors is modulated by their reversible phosphorylation. The kinases and phosphatases involved in these posttranslational modifications significantly contribute to AS regulation and to its integration in the complex regulative network that controls gene ex...

Functional coupling of transcription and splicing

Gene, 2012

The tightly regulated process of precursor messenger RNA (pre-mRNA) alternative splicing is a key mechanism to increase the number and complexity of proteins encoded by the genome. Evidence gathered in recent years has established that transcription and splicing are physically and functionally coupled and that this coupling may be an essential aspect of the regulation of splicing and alternative splicing. Recent advances in our understanding of transcription and of splicing regulation have uncovered the multiple interactions between components from both types of machinery. These interactions help to explain the functional coupling of RNAPII transcription and pre-mRNA alternative splicing for efficient and regulated gene expression at the molecular level. Recent technological advances, in addition to novel cell and molecular biology approaches, have led to the development of new tools for addressing mechanistic questions to achieve an integrated and global understanding of the functional coupling of RNAPII transcription and pre-mRNA alternative splicing. Here, we review major milestones and insights into RNA polymerase II transcription and pre-mRNA alternative splicing as well as new concepts and challenges that have arisen from multiple genome-wide approaches and analyses at the single-cell resolution.

In Brief: (mis)splicing in disease

The Journal of pathology, 2014

Splicing of pre-mRNAs is a crucial step in the gene expression pathway. Disruption of splicing has been linked to the pathogenesis of several human diseases and is particularly widespread in cancer. Recently, a number of mutations affecting genes of the core spliceosome machinery have been identified in haematological malignancies, yet the effect of such mutations on RNA splicing is unclear. A better understanding of how mis-splicing contributes to malignancies may provide diagnostic or prognostic information and new drug targets for therapeutic approaches.

A Broad Set of Chromatin Factors Influences Splicing

PLOS Genetics, 2016

Several studies propose an influence of chromatin on pre-mRNA splicing, but it is still unclear how widespread and how direct this phenomenon is. We find here that when assembled in vivo, the U2 snRNP co-purifies with a subset of chromatin-proteins, including histones and remodeling complexes like SWI/SNF. Yet, an unbiased RNAi screen revealed that the outcome of splicing is influenced by a much larger variety of chromatin factors not all associating with the spliceosome. The availability of this broad range of chromatin factors impacting splicing further unveiled their very context specific effect, resulting in either inclusion or skipping, depending on the exon under scrutiny. Finally, a direct assessment of the impact of chromatin on splicing using an in vitro co-transcriptional splicing assay with pre-mRNAs transcribed from a nucleosomal template, demonstrated that chromatin impacts nascent pre-mRNP in their competence for splicing. Altogether, our data show that numerous chromatin factors associated or not with the spliceosome can affect the outcome of splicing, possibly as a function of the local chromatin environment that by default interferes with the efficiency of splicing.