interaction of nucleoside diphosphate kinase B with Gβγ dimers controls heterotrimeric G protein function

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 106; no. 38; pp. 16269 - 16274
• Main Authors: Hippe, Hans-Joerg, Wolf, Nadine M, Abu-Taha, Issam, Mehringer, Rebecca, Just, Steffen, Lutz, Susanne, Niroomand, Feraydoon, Postel, Edith H, Katus, Hugo A, Rottbauer, Wolfgang, Wieland, Thomas
• Format: Journal Article
• Language: English
• Published: National Academy of Sciences 2009
• Subjects: adenylate cyclase; cyclic AMP; Danio rerio; fibroblasts; humans; knockout mutants; nucleoside-diphosphate kinase; phenotype; protein content; scaffolding proteins
• ISSN: 0027-8424; 1091-6490

Heterotrimeric G proteins in physiological and pathological processes have been extensively studied so far. However, little is known about mechanisms regulating the cellular content and compartmentalization of G proteins. Here, we show that the association of nucleoside diphosphate kinase B (NDPK B) with the G protein βγ dimer (Gβγ) is required for G protein function in vivo. In zebrafish embryos, morpholino-mediated knockdown of zebrafish NDPK B, but not NDPK A, results in a severe decrease in cardiac contractility. The depletion of NDPK B is associated with a drastic reduction in Gβ₁γ₂ dimer expression. Moreover, the protein levels of the adenylyl cyclase (AC)-regulating Gαs and Gαi subunits as well as the caveolae scaffold proteins caveolin-1 and -3 are strongly reduced. In addition, the knockdown of the zebrafish Gβ₁ orthologs, Gβ₁ and Gβ₁like, causes a cardiac phenotype very similar to that of NDPK B morphants. The loss of Gβ₁/Gβ₁like is associated with a down-regulation in caveolins, AC-regulating Gα-subunits, and most important, NDPK B. A comparison of embryonic fibroblasts from wild-type and NDPK A/B knockout mice demonstrate a similar reduction of G protein, caveolin-1 and basal cAMP content in mammalian cells that can be rescued by re-expression of human NDPK B. Thus, our results suggest a role for the interaction of NDPK B with Gβγ dimers and caveolins in regulating membranous G protein content and maintaining normal G protein function in vivo.