synembryn-A (protein Ric-8A, RIC8A)

Function

• guanine nucleotide exchange factor
• can activate some, but not all, G-alpha proteins
• able to activate GNAI1, GNAO1 & GNAQ, but not GNAS by exchanging bound GDP for free GTP
• role in regulation of microtubule pulling forces during mitotic movement of chromosomes by stimulating Gi-alpha protein, possibly leading to release Gi-alpha-GTP & NuMA proteins from the NuMA-GPSM2-Gi-alpha-GDP complex
• activator for Gq-alpha (GNAQ)protein by enhancing the Gq-coupled receptor-mediated ERK activation
• interacts with GDP-bound G alpha proteins GNAI1, GNAO1 & GNAQ, & with GNA13 with lower affinity
• does not interact with G-alpha proteins when they are in complex with subunits beta & gamma (putative)
• phosphorylated upon DNA damage, probably by ATM or ATR

Structure

belongs to the synembryn family

Compartment

cytoplasm (putative)

Alternative splicing

named isoforms=3

More general terms

• guanine nucleotide exchange factor
• phosphoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q9NPQ8.html