Carboxyl terminal of G protein beta subunit is required for association with gamma subunit.
To investigate a complex formation of heterotrimeric G protein beta and gamma subunits, we constructed a deletion mutant which lacked the C-terminal WD40 repeating unit of beta 1 and cotransfected into HEK293 cells with gamma 2 which was tagged with FLAG-epitope. Co-immunoprecipitation assay indicated that the mutant beta 1 failed to associate with FLAG gamma 2. Furthermore, from the analysis of additional deletion mutants, the last 10 amino acids of C-terminal region of beta 1 were found to be necessary to associate with gamma 2. These results suggest that the C-terminal region, in addition to the N-terminal alpha-helical structure, of beta subunit may be involved in the beta gamma complex formation.
Yamauchi
J
J
Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Kaziro
Y
Y
Itoh
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D002460:Cell Line; D017931:DNA Primers; D019204:GTP-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007668:Kidney; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D016324:Sequence Tagged Sites; D014162:Transfection
D017931:DNA Primers; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D019204:GTP-Binding Proteins