tailieunhanh - Báo cáo khoa học: Identification of a novel alternative splicing variant of RGS5 mRNA in human ocular tissues

Regulator of G protein signaling (RGS) proteins act as GTPase-activating proteins (GAPs) for Gasubunits and negatively regulate G protein-coupled receptor signaling. Using RGS5 gene-specific RT-PCR, we have identified a novel alternative splicing variant of RGS5 mRNA in human ocular tissues. The alternative splicing of RGS5 mRNA occurred at position +44 (GenBank NM_003617), spliced out 174 bp (+44 to +218 bp) of the cod-ing region, and encoded an RGS5s protein with a 108 amino acid N-ter-minal deletion. . | ềFEBS Journal Identification of a novel alternative splicing variant of RGS5 mRNA in human ocular tissues Yanbin Liang Chen Li Victor M. Guzman William W. Chang Albert J. Evinger III Dyna Sao and David F. Woodward Department of BiologicalScience Allergan Inc. Irvine CA USA Keywords alternative splicing cannibinoid receptor G protein prostaglandin FP receptor RGS5 Correspondence Y. Liang Department of BiologicalScience Allergan Inc. Irvine CA 92612 USA Tel 1 714 2465966 Fax 1 714 2465578 E-mail Liang_Yanbin@ Received 14 June 2004 revised 2 November 2004 accepted 6 December 2004 doi Regulator of G protein signaling RGS proteins act as GTPase-activating proteins GAPs for Ga subunits and negatively regulate G protein-coupled receptor signaling. Using RGS5 gene-specific RT-PCR we have identified a novel alternative splicing variant of RGS5 mRNA in human ocular tissues. The alternative splicing of RGS5 mRNA occurred at position 44 GenBank NM_003617 spliced out 174 bp 44 to 218 bp of the coding region and encoded an RGS5s protein with a 108 amino acid N-ter-minal deletion. This study is the first to document alternative splicing of an RGS5 gene. We therefore studied RGS5 and RGS5s mRNA distribution in human tissues. In the eye RGS5s was found to be highly expressed in the ciliary body and trabecular meshwork. It was also expressed in the kidney brain spleen skeletal muscle and small intestine but was not detectable in the liver lung heart. RGS5s was not found in monkey and rat ocular tissues indicating species specificity for the eye. Comparing the recombinant RGS5 and RGS5s expression in HEK293 EBNA cells RGS5s was present almost exclusively in the cytosolic fraction whereas RGS5 was present in both membrane and cytosolic fractions. The data suggest that the N-terminal of RGS5 may be important for protein translocation to the cell membrane. Both RGS5 and RGS5s antagonized the rapid phosphorylation of p44 42 MAP kinase induced