PPP2CB Gene - Protein Phosphatase 2 Catalytic Subunit Beta | Function, Mutations & Disease

PPP2CB encodes the beta isoform of the catalytic subunit of protein phosphatase 2A (PP2A), one of the four major serine/threonine phosphatases. PP2A is a heterotrimeric holoenzyme composed of a structural A subunit, a regulatory B subunit, and a catalytic C subunit. The catalytic subunit encoded by PPP2CB is responsible for dephosphorylating key cellular substrates, thereby regulating cell cycle progression, DNA replication, transcription, apoptosis, and signal transduction pathways such as Wnt, PI3K/AKT, and MAPK. PPP2CB is widely expressed and functions as a tumor suppressor; its loss or mutation contributes to oncogenesis.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• PP2A-mediated dephosphorylation (Reactome: R-HSA-163615)

• Signaling by Wnt (Reactome: R-HSA-195721)

• PI3K/AKT signaling (KEGG: hsa04151)

• MAPK signaling pathway (KEGG: hsa04010)

• Cell cycle (KEGG: hsa04110)

The PPP2CB protein (UniProt P62714) is 309 amino acids long and belongs to the serine/threonine phosphatase family. It forms the catalytic core of the PP2A holoenzyme, which is essential for dephosphorylating a wide range of substrates including AKT, ERK, and beta-catenin. The protein contains a conserved phosphatase domain and is regulated by post-translational modifications such as methylation and phosphorylation. PPP2CB is ubiquitously expressed and its activity is critical for maintaining cellular homeostasis; dysregulation is linked to multiple cancers and neurodevelopmental disorders.