PIK3R1 Gene

The PIK3R1 gene (PIK3R1 stands for "phosphoinositide 3-kinase regulatory subunit 1") is a protein-coding gene located on chromosome 5q13.1. Alternative splicing of this gene results in four transcript variants encoding different isoforms.

Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-primary position. The enzyme consists of a catalytic subunit of 110 kD and a regulatory subunit of either 85, 55, or 50 kD. This gene encodes the 85 kD regulatory subunit. The phosphatidylinositol 3-kinases are responsible for coordinating a variety of cellular functions, including proliferation and survival (Lin C et al. 2011).

Phosphatidylinositol 3-kinase plays an important role in the metabolic action of insulin. A mutation in this gene has been associated with insulin resistance .

Diseases associated with PIK3R1 include:

• Short syndrome
• and
• Agammaglobulinemia 7, autosomal recessive.

1. Aarskog D et al (1983) Autosomal dominant partial lipodystrophy associated with Rieger anomaly, short stature, and insulinopenic diabetes. Am J Med Genet 15: 29-38.
2. Lin C et al (2011) Tyrosine phosphorylation of the Gα-interacting protein GIV promotes activation of phosphoinositide 3-kinase during cell migration. Sci Signal 4(192):ra64.
3. Sensenbrenner JA et al (1975) A low birthweight syndrome, ?Rieger syndrome. Birth Defects Orig Art Ser XI(2): 423-426.