TY - JOUR
T1 - Receptor-mediated activation of heterotrimeric G-proteins
T2 - Current structural insights
AU - Johnston, Christopher A.
AU - Siderovski, David P.
PY - 2007/8
Y1 - 2007/8
N2 - G-protein-coupled receptors (GPCRs) serve as catalytic activators of heterotrimeric G-proteins (Gαβγ) by exchanging GTP for the bound GDP on the Gα subunit. This guanine nucleotide exchange factor activity of GPCRs is the initial step in the G-protein cycle and determines the onset of various intracellular signaling pathways that govern critical physiological responses to extracellular cues. Although the structural basis for many steps in the G-protein nucleotide cycle have been made clear over the past decade, the precise mechanism for receptor-mediated G-protein activation remains incompletely defined. Given that these receptors have historically represented a set of rich drug targets, a more complete understanding of their mechanism of action should provide further avenues for drug discovery. Several models have been proposed to explain the communication between activated GPCRs and Gαβγ leading to the structural changes required for guanine nucleotide exchange. This review is focused on the structural biology of G-protein signal transduction with an emphasis on the current hypotheses regarding Gαβγ activation. We highlight several recent results shedding new light on the structural changes in Gα that may underlie GDP release.
AB - G-protein-coupled receptors (GPCRs) serve as catalytic activators of heterotrimeric G-proteins (Gαβγ) by exchanging GTP for the bound GDP on the Gα subunit. This guanine nucleotide exchange factor activity of GPCRs is the initial step in the G-protein cycle and determines the onset of various intracellular signaling pathways that govern critical physiological responses to extracellular cues. Although the structural basis for many steps in the G-protein nucleotide cycle have been made clear over the past decade, the precise mechanism for receptor-mediated G-protein activation remains incompletely defined. Given that these receptors have historically represented a set of rich drug targets, a more complete understanding of their mechanism of action should provide further avenues for drug discovery. Several models have been proposed to explain the communication between activated GPCRs and Gαβγ leading to the structural changes required for guanine nucleotide exchange. This review is focused on the structural biology of G-protein signal transduction with an emphasis on the current hypotheses regarding Gαβγ activation. We highlight several recent results shedding new light on the structural changes in Gα that may underlie GDP release.
UR - http://www.scopus.com/inward/record.url?scp=34547157646&partnerID=8YFLogxK
U2 - 10.1124/mol.107.034348
DO - 10.1124/mol.107.034348
M3 - Short survey
C2 - 17430994
AN - SCOPUS:34547157646
SN - 0026-895X
VL - 72
SP - 219
EP - 230
JO - Molecular Pharmacology
JF - Molecular Pharmacology
IS - 2
ER -