The regulator of G protein signaling RGS9 supports insulin secretion in male mouse islets

RGS9 supports glucose- and KCl-stimulated insulin secretion in male mouse pseudo-islets, with shRNA knockdown impairing secretion while leaving insulin content unchanged.

• Why it matters: RGS9 is enriched in islets, but its cellular localization and physiological role in insulin secretion were unclear, limiting understanding of how Gi/o signaling is tuned in beta cells.
• What they did: Rgs9 expression was mapped in mouse endocrine pancreas by RNA in situ hybridization and FACS with quantitative PCR, then tested by shRNA knockdown in wild-type and Rgs9{Delta}DEP/{Delta}DEP pseudo-islets.
• The result: Rgs9 knockdown impaired glucose- and KCl-stimulated insulin secretion in wild-type pseudo-islets, whereas Rgs9{Delta}DEP/{Delta}DEP islets did not show the same phenotype; persistent Rgs9 transcripts in mutants enabled knockdown to impair secretion.