A guanine nucleotide-binding regulatory protein (G protein), with subunits designated as α40βγ, was identified and partially resolved from two other purified G proteins, G0 (α39βγ) and G(i) (α41βγ), found in bovine brain. The α40 G protein subunit served as a substrate for ADP-ribosylation catalyzed by Bordetella pertussis toxin, as did α39 and α41·α40 was shown to be closely related to, but distinct from, α41 by reaction with various peptide antisera. An antiserum generated against a peptide derived from the sequence of a G(iα) clone isolated from a rat C6 glioma cDNA library (Itoh, H., Kozasa, T., Nagata, S., Nakamura, S., Katada, T., Ui, M., Iwai, S., Ohtsuka, E., Kawasaki, H., Suzuki, K., and Kaziro, Y. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 3776-3780) reacted with α40 to the exclusion of all other α subunits tested. Another antiserum generated against a peptide derived from an analogous region of a different G(iα) clone from a bovine brain cDNA library (Nukuda, T., Tanabe, T., Takahashi, H., Noda, M., Haga, K., Haga, T., Ichiyama, A., Kangawa, K., Hiranaga, M., Matsuo, H., and Numa, S. (1986) FEBS Lett. 197, 305-310) reacted exclusively with α41. Evidence is given for the existence of another form of α41 that did not react with either of these two peptide antisera. The antisera were used to survey various rat tissues for the expression of α40 and α41.
|Number of pages||7|
|Journal||Journal of Biological Chemistry|
|State||Published - 1988|