Poster abstracts
Poster number 28 submitted by Gandhar Datar
Rbfox2 plays a major role in regulating alternative splicing in the adult liver
Gandhar Datar (School of Molecular and Cellular Biology, University of Illinois Urbana-Champaign), Waqar Arif (School of Molecular and Cellular Biology, Department of Biochemistry, College of Medicine, University of Illinois Urbana-Champaign), Amruta Bhate (Department of Biochemistry, University of Illinois Urbana-Champaign), Auinash Kalsotra (School of Molecular and Cellular Biology, Department of Biochemistry, College of Medicine, University of Illinois Urbana-Champaign)
Abstract:
Alternative splicing (AS) is a key gene regulatory mechanism that supports normal liver development and function. Aberrant AS has been cited to cause abnormal development and disease pathologies. Splicing factors are an essential component of this type of regulation, increasing or decreasing the expression of certain isoforms by binding to pre-mRNA as part of a spliceosome complex. Rbfox2, a member of the RNA-binding FOX (Rbfox) family of splicing factors is known as a master tissue-specific factor, regulating splicing of many genes including other splicing factors in the brain, muscle, and embryonic stem cells. While the role of Rbfox2 is well-defined in neural and muscle tissues; its function as a splicing regulatory factor in the liver is not understood. We generated a liver-specific knockout (LKO) of Rbfox2 using an albumin-driven CRE recombinase and characterized alternative splicing regulation in Rbfox2-deficient hepatocytes. Splicing assays analyzing the isoforms of over 100 developmentally regulated genes were performed in adult WT and Rbfox2 LKO mice. Several key genes that control hepatic growth showed strong splicing defects including Nf2, an upstream regulator of the Hippo Pathway, and NPRL3, a member of the GATOR1 complex inhibiting the TORC1 Pathway. In addition, histological analysis revealed early onset of fibrosis in LKOs. An integrative analysis of ENCODE generated eCLIP and RNA-seq data from Rbfox2 depleted HepG2 liver cells is being currently analyzed to uncover Rbfox2’s direct gene targets in hepatocytes. Taken together, our results define a critical role for Rbfox2 in regulating hepatocyte-specific splicing and maintaining appropriate liver functioning.
Keywords: Alternative Splicing, Liver, Regulation