G-protein-signaling modulator 1 (activator of G-protein signaling 3, GPSM1, AGS3)

Function

• guanine nucleotide dissociation inhibitor (GDI)
• receptor-independent activator of heterotrimeric G-protein signaling
• keeps G(i/o) alpha in GDP-bound form thus uncoupling heterotrimeric G-proteins signaling from G protein-coupled receptors
• controls spindle orientation & asymmetric cell fate of cerebral cortical progenitors
• role in macroautophagy in intestinal cells (putative)
• interacts with GNAI1, GNAI2 & GNAI3 preferentially in their GDP-bound state
• may also interact with GNAO1
• interacts with STK11/LKB1 & MACF1
• interacts with INSC/inscuteable
• phosphorylation regulates interactions with G(i/o) alpha

Structure

• belongs to the GPSM family
• contains 4 GoLoco domains
  • mediate interaction with G(i/o) alpha
  • essential for the GDI activity toward G(i/o) alpha
• contains 9 TPR repeats

Compartment

• cytoplasm,
• endoplasmic reticulum membrane, Golgi membrane
• peripheral membrane, cytoplasmic side

Alternative splicing

named isoforms=3

Expression

expressed in intestinal cells

Pathology

role in drug addiction

More general terms

• G-protein-signaling modulator (GPSM)
• phosphoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q86YR5.html