Phosphoinositide 3-kinase gamma adapter protein p101 subunit

Class I PI3Ks are dual-specific lipid and protein kinases involved in numerous intracellular signaling pathways. Class IB PI3K, p110gamma, is mainly activated by seven-transmembrane G-protein-coupled receptors (GPCRs), through its regulatory subunit p101 and G-protein beta-gamma subunits [1].

Literature references

1. Vanhaesebroeck B, Leevers SJ, Ahmadi K, Timms J, Katso R, Driscoll PC, Woscholski R, Parker PJ, Waterfield MD; , Annu Rev Biochem. 2001;70:535-602.: Synthesis and function of 3-phosphorylated inositol lipids. PUBMED:11395417

InterPro entry IPR019522

Protein kinases are a group of enzymes that possess a catalytic subunit which transfers the gamma phosphate from nucleotide triphosphates (often ATP) to one or more amino acid residues in a protein substrate side chain, resulting in a conformational change affecting protein function. The enzymes fall into two broad classes, characterised with respect to substrate specificity: serine/threonine specific and tyrosine specific PUBMED:3291115.

Protein kinase function has been evolutionarily conserved from Escherichia coli to human. Protein kinases play a role in a multitude of cellular processes, including division, proliferation, apoptosis, and differentiation PUBMED:12368087. Phosphorylation usually results in a functional change of the target protein by changing enzyme activity, cellular location, or association with other proteins.

The catalytic subunits of protein kinases are highly conserved, and several structures have been solved PUBMED:15078142, leading to large screens to develop kinase-specific inhibitors for the treatments of a number of diseases PUBMED:15320712.

Class I PI3Ks are dual-specific lipid and protein kinases involved in numerous intracellular signaling pathways. Class IB PI3K, p110gamma, is mainly activated by seven-transmembrane G-protein-coupled receptors (GPCRs) through its regulatory subunit p101 and G-protein beta-gamma subunits PUBMED:11395417.

PI3K is a lipid kinase and a key signalling enzyme involving in cell survival and proliferation, cell motility and adhesion, cytoskeletal rearrangement and vesicle trafficking PUBMED:10579926. The different PI3K isoforms have cell-specific functions. In yeast, VPS34 is a key enzyme required for cell division, vacuolar protein sorting, and vacuole segregation PUBMED:8385367. The major components of the yeast VPS intracellular trafficking complex are conserved in humans PUBMED:7628435.

There are three major classes of PI3Ks, I and III (Class I is also subdivided into Ia and Ib), and a more distantly related Class IV which contains Ser/Thr kinases. The different classes of PI3K catalyse phosphorylation of the 3'-OH position of phosphatidyl myo-inositol (PtdIns) lipids, generating different 3'-phosphorylated lipid products that act as secondary messengers. The classification of PI3Ks is based upon sequence analysis and domain architecture of the catalytic subunits, but the divisions also reflect the biochemical properties and the differential association with a variety of regulatory adaptor subunits.

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Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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