TPPP
Description
The TPPP (tubulin polymerization promoting protein) is a protein-coding gene located on chromosome 5.
Tubulin polymerization-promoting protein is a protein that in humans is encoded by the TPPP gene. This protein has been linked to multiple sclerosis myelin lesions and CSF abnormalities in multiple sclerosis patients.
TPPP is a regulator of microtubule dynamics, playing a crucial role in myelination by promoting elongation of the myelin sheath. It acts as a microtubule nucleation factor in oligodendrocytes, specifically localizing to the Golgi outpost region and promoting microtubule nucleation, an essential step for myelin sheath elongation. TPPP is required for both uniform polarized growth of distal microtubules and the direction of proximal process branching. It exhibits magnesium-dependent GTPase activity, though its function remains unclear. Beyond microtubule nucleation, TPPP is involved in microtubule bundling and stabilization, maintaining the integrity of the microtubule network. TPPP regulates microtubule dynamics by promoting tubulin acetylation, achieved by inhibiting the tubulin deacetylase activity of HDAC6. Furthermore, TPPP regulates cell migration, phosphorylation by ROCK1 inhibits interaction with HDAC6, leading to decreased tubulin acetylation and increased cell motility. It plays a role in cell proliferation by regulating the G1/S-phase transition. TPPP is involved in astral microtubule organization and mitotic spindle orientation during early mitosis, a process regulated by phosphorylation by LIMK2.
TPPP is also known as TPPP/p25, TPPP1, p24, p25, p25alpha.
