PPP2R1A

Description

The PPP2R1A (protein phosphatase 2 scaffold subunit Aalpha) is a protein-coding gene located on chromosome 19.

Serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform is an enzyme that in humans is encoded by the PPP2R1A gene. In the plant Arabidopsis thaliana a similar enzyme is encoded by the RCN1 gene (At1g25490). This gene encodes a constant regulatory subunit of protein phosphatase 2. Protein phosphatase 2 is one of the four major Ser/Thr phosphatases, and it is implicated in the negative control of cell growth and division. It consists of a common heteromeric core enzyme, which is composed of a catalytic subunit and a constant regulatory subunit, that associates with a variety of regulatory subunits. The constant regulatory subunit A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit. This gene encodes an alpha isoform of the constant regulatory subunit A. RCN1 At1g25490 is one of three genes in Arabidopsis encoding Phosphoprotein Phosphatase 2A Regulatory Subunit A (PP2Aa). The association of different b subunits with a PP2Aa-PP2ac dimer is believed to determine substrate specificity.

The PR65 subunit of protein phosphatase 2A (PP2A) acts as a scaffolding molecule, facilitating the assembly of the catalytic subunit and a variable regulatory B subunit. Interaction with GNA12 leads to dephosphorylation of the microtubule-associated protein TAU/MAPT (PubMed:15525651). Proper chromosome segregation and centromeric localization of SGO1 during mitosis are dependent on this gene (PubMed:16580887). In conjunction with the RACK1 adapter, it mediates dephosphorylation of AKT1 at 'Ser-473', inhibiting AKT1 activation and the AKT-mTOR signaling pathway (By similarity). Dephosphorylation of AKT1 is crucial for the homeostasis and stability of regulatory T-cells (Treg) (By similarity).

PPP2R1A is also known as HJS2, MRD36, PP2A-Aalpha, PP2AA, PP2AAALPHA, PR65A.

Associated Diseases

• Mental retardation, autosomal dominant 36
• Microcephaly-corpus callosum hypoplasia-intellectual disability-facial dysmorphism syndrome