Activation of the G protein Gq/11 through tyrosine phosphorylation of the α subunit

Hisashi Umemori*, Takafumi Inoue, Shoen Kume, Naohiro Sekiyama, Motoshi Nagao, Hiroshi Itoh, Shigetada Nakanishi, Katsuhiko Mikoshiba, Tadashi Yamamoto

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

128 Citations (Scopus)


Various receptors coupled to the heterotrimeric guanine nucleotide- binding protein Gq/11 stimulate formation of inositol-1,4,5-trisphosphate (IP3). Activation of these receptors also induces protein tyrosine phosphorylation. Formation of IP3 in response to stimulated receptors that couple to Gq/11 was blocked by protein tyrosine kinase inhibitors. These inhibitors appeared to act before activation of Gq/11. Moreover, stimulation of receptors coupled to Gq/11 induced phosphorylation on a tyrosine residue (Tyr356) of the Gα(q/11) subunit, and this tyrosine phosphorylation event was essential for Gq/11 activation. Tyrosine phosphorylation of Gα(q/11) induced changes in its interaction with receptors. Therefore, tyrosine phosphorylation of Gα(q/11) appears to regulate the activation of Gq/11 protein.

Original languageEnglish
Pages (from-to)1878-1881
Number of pages4
Issue number5320
Publication statusPublished - 1997 Jun 20
Externally publishedYes

ASJC Scopus subject areas

  • General


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