protein phosphatase type 2A complex

Definition

Target type: cellularcomponent

A protein complex that has protein serine/threonine phosphatase activity that is polycation-stimulated (PCS), being directly stimulated by protamine, polylysine, or histone H1; it constitutes a subclass of several enzymes activated by different histones and polylysine, and consists of catalytic, scaffolding, and regulatory subunits. The catalytic and scaffolding subunits form the core enzyme, and the holoenzyme also includes the regulatory subunit. [GOC:mah, ISBN:0198547684, PMID:17245430]

Protein phosphatase 2A (PP2A) is a highly conserved serine/threonine phosphatase that plays a critical role in regulating a wide range of cellular processes, including signal transduction, cell growth, proliferation, and apoptosis. The PP2A holoenzyme is a heterotrimeric complex consisting of three subunits: a structural A subunit, a catalytic C subunit, and a regulatory B subunit. The A subunit is a scaffold protein that provides the structural framework for the complex and is responsible for binding to the B subunit. The C subunit contains the catalytic activity of the phosphatase and is responsible for dephosphorylating target proteins. The B subunit is a diverse family of proteins that can regulate the activity and substrate specificity of the complex. There are four main families of B subunits: B, B', B'', and B''', each with distinct structural features and regulatory functions. The B subunits bind to the A subunit through a conserved motif and can influence the activity of the phosphatase by: (1) targeting the complex to specific cellular locations; (2) interacting with specific substrates; (3) modulating the catalytic activity of the C subunit. The B subunit can also act as a regulatory switch, turning the phosphatase on or off in response to specific cellular signals. The PP2A holoenzyme is a dynamic complex that can assemble and disassemble in response to cellular cues, allowing it to respond to a variety of cellular signals and regulate a wide range of cellular processes. The cellular component of PP2A complex refers to the specific location within the cell where the PP2A complex is found. PP2A is widely distributed throughout the cell and is found in both the cytoplasm and the nucleus. In the cytoplasm, PP2A is associated with various cellular structures, including the cytoskeleton, the endoplasmic reticulum, and the Golgi apparatus. In the nucleus, PP2A is involved in the regulation of gene expression and DNA replication. The specific localization of PP2A can vary depending on the cell type and the cellular context. For example, in some cells, PP2A is highly concentrated in the centrosome, a microtubule-organizing center that plays a key role in cell division. In other cells, PP2A is concentrated in the nucleus, where it regulates gene expression. The cellular component of PP2A complex is therefore highly dynamic and can change depending on the cellular needs.'
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Proteins (4)

Compounds (4)