Increased ubiquitination and the crosstalk of G protein signaling in cardiac myocytes: Involvement of Ric-8B in Gs suppression by Gq signal

Riris I. Jenie, Motoki Nishimura, Mika Fujino, Michio Nakaya, Norikazu Mizuno, Kenji Tago, Hitoshi Kurose, Hiroshi Itoh

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

Hyperactivation of Gq signaling causes cardiac hypertrophy, and β-adrenergic receptor-mediated Gs signaling is attenuated in hypertrophic cardiomyocytes. Here, we found the increase in a global ubiquitination in hypertrophic mouse heart. The activation of Gq signaling resulted in the ubiquitination of Gαs in neonatal rat cardiomyocytes, reduced Gαs expression, and suppressed cAMP response to β-adrenergic receptor stimulation. Ectopic expression of Gαq induced a similar suppression, which is due to the degradation of Gαs by a ubiquitin-proteasome pathway. Co-expression of Ric-8B, a positive regulator of Gαs, effectively canceled the Gαq-induced ubiquitination of Gαs and recovered the cAMP accumulation. In vitro, Gαq competes for the binding of Gαs to Ric-8B. These data show a new role of Ric-8B in the crosstalk of two distinct G protein signaling pathways, which are possibly involved in a part of mechanisms of chronic heart failure.

Original languageEnglish
Pages (from-to)1095-1106
Number of pages12
JournalGenes to Cells
Volume18
Issue number12
DOIs
Publication statusPublished - Dec 2013

All Science Journal Classification (ASJC) codes

  • Genetics
  • Cell Biology

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