Molecular cloning and characterization of Xenopus RGS5

We identified sis genes that encode putative RGS proteins (XRGSI-VI) in dev eloping Xenopus embryos using PCR amplification with degenerate primers cor responding to the conserved region (RGS domain) of known RGS proteins. RT-P CR analysis revealed that mRNAs of these XRGSs are differentially expressed during embryogenesis. At stage 1, only XRGSII mRNA was detected On the oth er hand, expression of SRGSVI mRNA increased apparently at stage 14 and exp ression of three of other XRGS (III, IV,V, elevated between stage 25 and 40 , To further characterize XRGS proteins expressed in Xenopus embryos, we is olated a cDNA clone for XRGSIII. Eased on determined nucleotide sequence, X RGSIII was considered as a Xenopus homologue of mammalian RGS5 (XRGS5), Gen etic analysis using the pheromone response halo assay showed that expressio n of XRGS5 inhibits yeast response to alpha-factor, suggesting that XRGS5 n egatively regulates the G-protein-mediated signaling pathway in developing Xenopus embryos, (C) 2000 Academic Press.