Molecular mechanisms of go signaling

Abstract

Go is the most abundant G protein in the central nervous system, where it comprises about 1% of membrane protein in mammalian brains. It functions to couple cell surface receptors to intercellular effectors, which is a critical process for cells to receive, interpret and respond to extracellular signals. Go protein belongs to the pertussis toxin-sensitive Gi/Go subfamily of G proteins. A number of G-protein-coupled receptors transmit stimuli to intercellular effectors through Go. Go regulates several cellular effectors, including ion channels, enzymes, and even small GTPases to modulate cellular function. This review summarizes some of the advances in Go research and proposes areas to be further addressed in exploring the functional role of Go.

Fig. 1

Protein sequence alignment of the human Gi/o family. Gly²/Ser⁶ motif for myristoylation and Cys³ for palmitoylation (bold), GTP-binding motif (GAGESGKS), Mg²⁺ -binding domain (DVGG), guanine ring-binding motif (NKKD), cysteine (∗) (at −4 from carboxyl terminal) for PTX ADP ribosylation on Gi/o proteins. Ggust is gustducin α subunit (gnat3). G_t sequence from cone transducin. Percentage of identity/homology. Spaces for alignment.

Fig. 2

Protein sequence alignment of Go protein across species. Percentage of identity/homology.

Fig. 3

Model of Go protein-mediated signal transduction.