Mordechai (Motti) Choder, PhD
Professor of Biology
PhD, 1988 - Weizmann Institute, Israel
A system view of gene expression
Gene expression was traditionally viewed as a linear process divided into distinct stages, e.g., transcription and translation. We have shown that this view is oversimplified. First, RNA polymerase II controls mRNA translation and decay, via a mediator – Rpb4/7. Second, many transcripts are “tagged” co-transcriptionally with factors, which later regulate mRNA localization, translatability and decay. We name this tagging “mRNA imprinting”. Remarkably, in addition to their well know role in transcription, promoter elements can regulate “mRNA imprinting”, thus affecting the mRNA fate in the cytoplasm. Third, we found that components of the “decaysome” complex, the major executioner of mRNAs degradation in the cytoplasm, also function as a transcription activator by physically associating with chromatin. Our findings demonstrate that gene expression is a circular process in which the hitherto first and last stages are interconnected. Finally, we propose that Rpb4/7 represents a novel class of factors, "mRNA coordinators", which integrate all stages of the gene expression process into a system. Hence, it is the coordinated integration of “distinct” stages of gene expression that determines the final expression signature of the genome.
See http://choder.net.technion.ac.il for further information.
Haimovich G, Medina AD, Causse SZ, Garber M, Millán-Zambrano G, Barkai O, Chávez S, Pérez-Ortín JE, Darzacq X, and Choder M. 2013. Gene expression is circular: factors for mRNA degradation also foster mRNA synthesis. Cell 153, 1000-1011.
Pérez-Ortín JE, Alepuz P, Chávez S, and Choder M. 2013. Eukaryotic mRNA decay: methodologies, pathways, and links to other stages of gene expression. J. Mol. Biol. 25, 3750-75.
Choder, M. 2011. mRNA imprinting: additional level in the regulation of gene expression. Cellular Logistics 1, 37-40.
Bregman A, Avraham-Kelbert M, Barkai O, Duek L, Guterman A, and Choder M. 2011. Promoter elements regulate cytoplasmic mRNA decay. Cell 147, 1473-83.
Harel-Sharvit L, Eldad N, Haimovich G, Barkai O, Duek L and Choder M. 2010. RNA polymerase II subunits link transcription and mRNA decay to translation. Cell 143, 552-563.
Conceptual illustration: Gene expression is a circular system. Integration of all the indicated stages is mediated by mRNA coordinators.