G(12) AND G(13) ALPHA-SUBUNITS ARE IMMUNOCHEMICALLY DETECTABLE IN MOST MEMBRANES OF VARIOUS MAMMALIAN-CELLS AND TISSUES

The cDNAs of two putatively pertussis toxin-insensitive G-protein α-subunits, α12 and α13 were recently cloned. mRNA analyses based on the reverse transcriptase polymerase chain reaction indicated a widespread distribution of both mRNAs [Strathmann, M. P., and Simon, M. 1. (1991) Proc. Nati. Acad. Sci. USA88, 5582-5586]. Generating specific antibodies directed against internal and C-terminal peptide sequences, we identified α12 protein in all and α13 protein in most tissues and cell lines tested. No species differences were observed, indicating a high degree of identity between mammalian species. Strong immunoreactive signals of both proteins were obtained in neuronal cell membranes of various species. Our results support the hypothesis that G12 and G13 are involved in pertussis toxin-insensitive pathways of signal transduction common to most tissues. © 1994 Academic Press, Inc.