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. This gene encodes the 85 kD regulatory subunit. 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. Alternative splicing of this gene results in four transcript variants encoding different isoforms. [provided by RefSeq, Jun 2011]

Tumor type associations:

  • Bladder
  • Breast
  • Cervical
  • Colorectal
  • Endometrial
  • Esophageal
  • Gastric
  • Kidney
  • Lymphoma
  • Melanoma
  • Ovarian
  • Pancreatic
  • Prostate
  • Enables phosphotyrosine residue binding¬†MAP kinase kinase activity
  • Enables transmembrane receptor protein tyrosine kinase adaptor activity
  • Enables insulin receptor binding
  • Enables insulin-like growth factor receptor binding
  • Enables neurotrophin TRKA receptor binding
  • Located in nucleus
  • Located in cytoplasm
  • Located in cis-Golgi network
  • Located in cytosol
  • Located in plasma membrane
  • Involved in cellular glucose homeostasis
  • Involved in negative regulation of cell-matrix adhesion
  • Involved in protein phosphorylation
  • Involved in protein import into nucleus
  • Negative regulation of cell adhesion
  • Agammaglobulinemia 7, autosomal recessive
  • Immunodeficiency 36
  • SHORT syndrome

PIK3R1 localizations – Subcellular Localization Database

EmwOwn work. Structure of the PIK3R1 protein. Based on PyMOL rendering of PDB 1bfi.

Gene Location