Phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2)

Phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2) encodes the p85β regulatory subunit of the Class IA phosphoinositide 3-kinase (PI3K) enzyme complex (UniProt P48567). This protein plays a critical role in the PI3K/Akt signaling pathway by stabilizing the p110 catalytic subunits and facilitating their recruitment to activated receptor tyrosine kinases at the cell membrane (PubMed: 22941191). While it acts as an inhibitor of p110 in the resting state, its recruitment and subsequent conformational changes are essential for PI3K activation in response to growth factors and insulin (PubMed: 22941191). Dysregulation of PIK3R2, through either gain-of-function mutations or overexpression, is strongly associated with oncogenesis in various tissues and developmental disorders such as Megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndrome (PubMed: 22729224). In the context of mRNA-targeted therapies, PIK3R2 mRNA is a focus for knockdown strategies using siRNA or antisense oligonucleotides to reduce p85β levels and dampen hyperactive PI3K signaling in cancer cells (PubMed: 25605863). Therapeutic intervention typically aims to disrupt the overactive signaling cascade to inhibit tumor growth and overcome resistance to other targeted therapies.

Other names

p85-betaP85BPhosphatidylinositol 3-kinase 85 kDa regulatory subunit betaPI3-kinase regulatory subunit betaMPPHMPPH1

Inhibition of the PI3K signaling pathway by targeting the catalytic subunit (p110) of the PI3K complex, which is stabilized and regulated by the PIK3R2-encoded p85β subunit, or through experimental knockdown of PIK3R2 mRNA using RNA interference.