Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform

PPP2R2A encodes a 55 kDa regulatory subunit (B alpha isoform) of protein phosphatase 2A (PP2A), a serine/threonine phosphatase complex. This substrate-recognition subunit is essential for PP2A-mediated cell cycle control, particularly by regulating dephosphorylation of WEE1 and MKI67 to coordinate mitosis entry and exit (UniProt: P63151).

PP2A regulatory subunits are broadly expressed across tissues and serve critical roles in phosphorylation-dependent signaling cascades. No disease associations are documented in UniProt curated records.

PPP2R2A is tagged as relevant to Alzheimer's Disease based on proteomics evidence from human post-mortem AD brain tissue. Analysis of four subcellular fractions (P2, P3, S2, S3) by TMT-labeled mass spectrometry revealed PPP2R2A is down-regulated in AD brain compared to age-matched controls (mean log2 fold-change: −0.20; Chaparral AD proteomics). This modest reduction in a PP2A regulatory subunit may relate to altered phosphorylation-dependent processes in neurodegeneration.