serine/threonine protein phosphatase 2A regulatory subunit B" subunit beta
Heterotrimeric serine/threonine protein phosphatase 2A (PP2A) consists of scaffolding (A), catalytic (C), and variable (B, B', and B") subunits. The variable subunits dictate subcellular localization and substrate specificity of the PP2A holoenzyme. This group contains protein phosphatase subunit PR70 (also known as protein phosphatase 2 regulatory subunit B'' subunit beta, PR48, NYREN8, PPP2R3L, or PPP2R3LY) that is encoded by the PPP2R3B gene. This substrate-recognizing subunit of PP2A has a two-domain elongated structure with two calcium EF-hands, each displaying different affinities to Ca2+. PPP2R3B/PR70 is a gonosomal melanoma tumor suppressor gene; PR70 decreased melanoma growth by negatively interfering with DNA replication and cell cycle progression through its role in stabilizing the cell division cycle 6 (CDC6)-chromatin licensing and DNA replication factor 1 (CDT1) interaction, which delays the firing of origins of DNA replication.