Received for publication July 16, 2007.
Revised July 16, 2007.
Accepted for publication July 16, 2007.

Illuminating G₅ Signaling (Relates to article by Yost, et al., Fast Forward 27 Jun 07)

Abstract

Guanine nucleotide binding proteins (G proteins) are key intermediates in cellular signaling and act in response to a variety of extracellular stimuli. The prevailing paradigm is that G protein subunits form a heterotrimeric complex, and function principally at the plasma membrane. However, there is growing evidence for localization at, and signaling by, G proteins at intracellular compartments. Moreover, different cellular pools of G proteins may be composed of distinct subunit subtypes, including some binding partners that function in the place of G protein subunits. An article in this issue of Molecular Pharmacology describes the use of an innovative fluorescent cell imaging technique to study interactions of the G protein ₅ subunit with a panel of G subunits as well as RGS proteins that contain a G-like subdomain. The approach used here provides a new strategy to elucidate the spatial and temporal properties of G proteins, including a growing number of atypical G pairings.

Key words: G protein regulation, RGS proteins