guanine nucleotide binding protein (G protein), q polypeptide | |
---|---|
Identifiers | |
Symbol | GNAQ |
Entrez | 2776 |
HUGO | 4390 |
OMIM | 600998 |
RefSeq | NM_002072 |
UniProt | P50148 |
Other data | |
Locus | Chr. 9 q21 |
guanine nucleotide binding protein (G protein), alpha 11 (Gq class) | |
---|---|
Identifiers | |
Symbol | GNA11 |
Entrez | 2767 |
HUGO | 4379 |
OMIM | 139313 |
RefSeq | NM_002067 |
UniProt | P29992 |
Other data | |
Locus | Chr. 19 p13.3 |
guanine nucleotide binding protein (G protein), alpha 14 | |
---|---|
Identifiers | |
Symbol | GNA14 |
Entrez | 9630 |
HUGO | 4382 |
OMIM | 604397 |
RefSeq | NM_004297 |
UniProt | O95837 |
Other data | |
Locus | Chr. 9 q21 |
guanine nucleotide binding protein (G protein), alpha 15 (Gq class) | |
---|---|
Identifiers | |
Symbol | GNA15 |
Entrez | 2769 |
HUGO | 4383 |
OMIM | 139314 |
RefSeq | NM_002068 |
UniProt | P30679 |
Other data | |
Locus | Chr. 19 p13.3 |
Gq protein (Gαq, or Gq/11) is a heterotrimeric G protein subunit that activates phospholipase C (PLC). PLC in turn hydrolyzes Phosphatidylinositol 4,5-bisphosphate (PIP2) to diacyl glycerol (DAG) and inositol trisphosphate (IP3) signal transduction pathway. DAG acts as a second messenger that activates Protein Kinase C (PKC) and IP3 helps in phosphorylation of some proteins.
There has been much debate about the naming of the Gαq. However, the "q" in the name is arbitrarily named and does not stand for anything in particular. This nomenclature came from Micheal Strathmann and Mel Simon after their discovery of the protein class in 1989. Essentially, the q designation comes from the fact that Michael Strathmann couldn't use the front end of the alphabet "because those early letters were already reserved for a number of classes of subunits, the Gz designation had been taken and Gx seemed too obvious -- and so Gq."
Gq proteins are class of G proteins which work to activate phospholipase C (PLC), participating in a variety of cellular signaling pathways.
The Gq protein works by activating PLC. PLC then cleaves a phospholipid. In the process, phosphatidylinositol 4,5-bisphosphate (PIP2) is cleaved into diacyl glycerol (DAG) and inositol 1,4,5-trisphosphate (IP3). DAG remains bound to the membrane, and IP3 is released as a soluble structure into the cytosol. IP3 then diffuses through the cytosol to bind to IP3 receptors, particular calcium channels in the endoplasmic reticulum (ER). These channels are specific to calcium and only allow the passage of calcium to move through. This causes the cytosolic concentration of calcium to increase, causing a cascade of intracellular changes and activity.