Structure of Galphaq-p63RhoGEF-RhoA complex reveals a pathway for the activation of RhoA by GPCRs.
The guanine nucleotide exchange factor p63RhoGEF is an effector of the heterotrimeric guanine nucleotide-binding protein (G protein) Galphaq and thereby links Galphaq-coupled receptors (GPCRs) to the activation of the small-molecular-weight G protein RhoA. We determined the crystal structure of the Galphaq-p63RhoGEF-RhoA complex, detailing the interactions of Galphaq with the Dbl and pleckstrin homology (DH and PH) domains of p63RhoGEF. These interactions involve the effector-binding site and the C-terminal region of Galphaq and appear to relieve autoinhibition of the catalytic DH domain by the PH domain. Trio, Duet, and p63RhoGEF are shown to constitute a family of Galphaq effectors that appear to activate RhoA both in vitro and in intact cells. We propose that this structure represents the crux of an ancient signal transduction pathway that is expected to be important in an array of physiological processes.
Lutz
Susanne
S
Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Maybachstrasse 14, D-68169 Mannheim, Germany.
Shankaranarayanan
Aruna
A
Coco
Cassandra
C
Ridilla
Marc
M
Nance
Mark R
MR
Vettel
Christiane
C
Baltus
Doris
D
Evelyn
Chris R
CR
Neubig
Richard R
RR
Wieland
Thomas
T
Tesmer
John J G
JJ
D000595:Amino Acid Sequence; D001665:Binding Sites; D002460:Cell Line; D018360:Crystallography, X-Ray; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000737:chemistry* / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D064067:Rho Guanine Nucleotide Exchange Factors; D015398:Signal Transduction; D020742:rhoA GTP-Binding Protein / Q000737:chemistry* / Q000378:metabolism
C475063:ARHGEF25 protein, human; D020662:Guanine Nucleotide Exchange Factors; D064067:Rho Guanine Nucleotide Exchange Factors; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020742:rhoA GTP-Binding Protein