Phosphatidylinositol 3-kinase regulatory subunit alpha is an enzyme that in humans is encoded by the PIK3R1 gene. [5]
Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The enzyme comprises a 110 kD catalytic subunit and a regulatory subunit of either 85, 55, or 50 kD. The Pik3r1 gene locus encodes the 85 kD regulatory subunit, as well as 55 and 50 kD regulatory subunits. It used to be thought that alternative splicing of this gene resulted in three transcript variants encoding different isoforms. [6] In fact, it has since been shown that the 55 and 50kD subunits have their own promotors within the gene locus Pik3r1. [7]
Phosphatidylinositol 3-kinase plays an important role in the metabolic actions of insulin, and a mutation in this gene has been associated with insulin resistance. [8] Suppression specifically of the 85kD subunit in early murine embryoid body development results in a transient cell-cell adhesion deficiency, mediated by transient downregulation of the adhesion molecule integrin-beta1 (ITGB1). [7]
Mutations in PIK3R1 are implicated in cases of breast cancer. [9]
Mutations in PIK3R1 are associated to SHORT syndrome. [10]
PIK3R1 has been shown to interact with:
Phosphoinositide 3-kinases (PI3Ks), also called phosphatidylinositol 3-kinases, are a family of enzymes involved in cellular functions such as cell growth, proliferation, differentiation, motility, survival and intracellular trafficking, which in turn are involved in cancer.
Tyrosine-protein phosphatase non-receptor type 11 (PTPN11) also known as protein-tyrosine phosphatase 1D (PTP-1D), Src homology region 2 domain-containing phosphatase-2 (SHP-2), or protein-tyrosine phosphatase 2C (PTP-2C) is an enzyme that in humans is encoded by the PTPN11 gene. PTPN11 is a protein tyrosine phosphatase (PTP) Shp2.
Adapter molecule crk also known as proto-oncogene c-Crk is a protein that in humans is encoded by the CRK gene.
JAK1 is a human tyrosine kinase protein essential for signaling for certain type I and type II cytokines. It interacts with the common gamma chain (γc) of type I cytokine receptors, to elicit signals from the IL-2 receptor family, the IL-4 receptor family, the gp130 receptor family. It is also important for transducing a signal by type I (IFN-α/β) and type II (IFN-γ) interferons, and members of the IL-10 family via type II cytokine receptors. Jak1 plays a critical role in initiating responses to multiple major cytokine receptor families. Loss of Jak1 is lethal in neonatal mice, possibly due to difficulties suckling. Expression of JAK1 in cancer cells enables individual cells to contract, potentially allowing them to escape their tumor and metastasize to other parts of the body.
RAC(Rho family)-alpha serine/threonine-protein kinase is an enzyme that in humans is encoded by the AKT1 gene. This enzyme belongs to the AKT subfamily of serine/threonine kinases that contain SH2 protein domains. It is commonly referred to as PKB, or by both names as "Akt/PKB".
Proto-oncogene tyrosine-protein kinase Fyn is an enzyme that in humans is encoded by the FYN gene.
Cbl is a mammalian gene family. CBL gene, a part of the Cbl family, encodes the protein CBL which is an E3 ubiquitin-protein ligase involved in cell signalling and protein ubiquitination. Mutations to this gene have been implicated in a number of human cancers, particularly acute myeloid leukaemia.
RAS p21 protein activator 1 or RasGAP, also known as RASA1, is a 120-kDa cytosolic human protein that provides two principal activities:
AKT2, also known as RAC-beta serine/threonine-protein kinase, is an enzyme that in humans is encoded by the AKT2 gene. It influences metabolite storage as part of the insulin signal transduction pathway.
Insulin receptor substrate 2 is a protein that in humans is encoded by the IRS2 gene.
GRB2-associated-binding protein 1 is a protein that in humans is encoded by the GAB1 gene.
Docking protein 1 is a protein that in humans is encoded by the DOK1 gene.
Phosphatidylinositol 3-kinase regulatory subunit beta is an enzyme that in humans is encoded by the PIK3R2 gene.
Protein tyrosine kinase 2 beta is an enzyme that in humans is encoded by the PTK2B gene.
RAC-gamma serine/threonine-protein kinase is an enzyme that in humans is encoded by the AKT3 gene.
Cytoplasmic protein NCK1 is a protein that in humans is encoded by the NCK1 gene.
Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta isoform is an enzyme that in humans is encoded by the PIK3CB gene.
Phosphatidylinositol-4-phosphate 3-kinase C2 domain-containing alpha polypeptide is an enzyme that in humans is encoded by the PIK3C2A gene.
The Akt signaling pathway or PI3K-Akt signaling pathway is a signal transduction pathway that promotes survival and growth in response to extracellular signals. Key proteins involved are PI3K and Akt.
In the field of biochemistry, PDPK1 refers to the protein 3-phosphoinositide-dependent protein kinase-1, an enzyme which is encoded by the PDPK1 gene in humans. It is implicated in the development and progression of melanomas.