| Modification Notes |
Protein phosphatase 2A (PP2A) is a major mammalian serine/threonine phosphatase that regulates diverse cellular processes. ANP32A, also known as Inhibitor 1 of PP2A (I1PP2A) is a heat-stable cytoplasmic and nuclear protein that functions as an inhibitor of cellular PP2A phosphatase activity. ANP32B (acidic (leucine-rich) nuclear phosphoprotein 32 family, member B), also designated PHAPI2, SSP29 or APRIL, is a 251 amino acid protein that localizes to the nucleus and contains four LRR (leucine-rich repeat) motifs. Expressed in placenta, heart, pancreas, lung, prostate, spleen and thymus, ANP32B exists as a multifunctional protein that plays an essential role in cell cycle progression and cell survival and is required for the G1 to S phase transition. Additionally, ANP32B functions as an anti-apoptotic factor that inhibits the activity of caspase-3, a protein that is crucial for the successful execution of apoptotic events. |