Talk abstracts

Talk on Tuesday 09:45-10:00am submitted by Guramrit Singh

Consequences of mRNA costume change

Justin Mabin, Lauren Woodward, Zhongxia Yi (Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, OH), Robert Patton, Ralf Bundschuh (Department of Physics, Center for RNA Biology, The Ohio State University, Columbus, OH), Mengxuan Jia, Vicki Wysocki (Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, OH), Guramrit Singh (Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, OH)

Abstract:
Throughout its lifetime, messenger RNA (mRNA) exists decorated with proteins as mRNA-protein particle, or mRNP. A key component of all spliced mRNPs is the exon junction complex (EJC), which assembles during pre-mRNA splicing 24 nucleotides (nt) upstream of exon-exon junctions. The stable EJC core thus assembled serves as an interaction platform for peripheral proteins that direct mRNA export, localization, translation and nonsense-mediated mRNA decay (NMD). Both mRNPs and EJCs and are widely presumed to be "dynamic" entities that change during an mRNAs lifetime. I will discuss our findings that the EJCs, and hence spliced mRNPs, undergo an extensive compositional overhaul after their export to cytoplasm. This compositional switch leads to a dramatic structural remodeling of the EJC from a multimeric mega-dalton sized RNP to its monomeric form. The change in EJC composition also leads to at least two distinct phases of the EJC-dependent NMD.

Keywords: messenger RNA, exon junction complex, nonsense-mediated mRNA decay