Poster abstracts

Poster number 75 submitted by Daniel L. Kiss

Surveillance of mRNAs by Distinct Exozymes

Daniel L. Kiss (1 Department of Molecular Biology and Microbiology, 2 Program in Cell Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4960, USA 2 Program in Cell Biology,), Erik D. Andrulis (1 Department of Molecular Biology and Microbiology, 2 Program in Cell Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4960, USA 2 Program in Cell Biology,)

Abstract:
ABSTRACT
Exosome complexes are composed of 10 to 11 subunits and are involved in multiple facets of 3’to 5’ RNA processing and turnover. The current paradigm stipulates that a uniform, stoichiometric core exosome, composed of single copies of each subunit, carries out all RNA metabolic functions attributed to the complex; however, available data raises questions about whether individual subunits contribute to RNA metabolic functions exclusively within the complex. We have proposed the exozyme hypothesis, a novel model stipulating that subsets of exosome subunits and cofactors assemble into a continuum of compositionally distinct complexes with different RNA specificities to resolve this discrepancy. Here, we test the predictions of the exozyme model via bioinformatic analysis of microarray data obtained from exosome subunit depleted cells. The transcriptomic analyses show individual depletion of individual exosome subunits contributes differentially to mRNA levels. Extending upon these findings will advance our understanding of the underlying mechanisms regulating RNA processing and turnover.

Keywords: Exosome, Exozyme, microarray