Recombinant human Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform (PP2A subunit B isoform B55-alpha), corresponding to amino acids 2-447, is a high-quality protein fragment designed for structural and biochemical studies. This fragment represents a stable and soluble unit of the protein, ideal for investigating its critical role in cell cycle regulation, including mitosis entry and exit.

The full-length Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform, encoded by the PPP2R2A gene in Homo sapiens, serves as a substrate-recognition subunit of protein phosphatase 2A (PP2A). It plays a key role in cell cycle control by regulating mitosis entry and exit, as demonstrated in studies (e.g., PubMed:1849734, PubMed:33108758). This protein is involved in chromosome clustering during late mitosis through dephosphorylation of MKI67 and is essential for PP2A-mediated dephosphorylation of WEE1. This action prevents WEE1 ubiquitin-mediated proteolysis, increases WEE1 protein levels, and promotes the G2/M checkpoint, highlighting its significance in maintaining genomic integrity and cell division processes.