Coling of the full-length gene of activin receptor-interacting protein2a and characterization of its interaction with ActR II A

To investigate the mechanism of intracellular signal transduction mediated by activin receptors, the full-length gene encoding a novel activin receptor-interacting protein2a (ARIP2a) was identified from a mouse brain cDNA library. The sequences of ARIP2a and ARIP2, distribution of ARIP2a and ARIP2 mRNA in mouse tissues, and expression of ARIP2a and ARIP2 in activin-induced RAW264. 7 cell were compared, and the interaction between ARIP2a and ActRIIA was confirmed. The sequences analysis revealed that the full-length gene of ARIP2a, which composed of 1008 bp and encoded 153 amino acid residues, shared high sequence indentity with ARIP2 except the position of the 99th amino acid. RT-PCR assay showed that ARIP2a mRNA was highly expressed in brain, pituitary and testis, and moderately in pancreas and ovary, but undetectable in other tissues. Whereas, ARIP2 mRNA was widely distributed in all mouse tissues that we tested. Moreover, expression of ARIP2a mRNA was significantly decreased in activin-stimula...