Human Tubulin Polymerization-promoting Protein, TPPP ELI

Regulator of microtubule dynamics that plays a key role in myelination by promoting elongation of the myelin sheath (PubMed: 31522887).

Acts as a microtubule nucleation factor in oligodendrocytes: specifically localizes to the postsynaptic Golgi apparatus region, also named Golgi outpost, and promotes microtubule nucleation, an important step for elongation of the myelin sheath (PubMed: 31522887).

Required for both uniform polarized growth of distal microtubules as well as directing the branching of proximal processes (PubMed: 31522887).

Shows magnesium-dependent GTPase activity; the role of the GTPase activity is unclear (PubMed: 21995432, PubMed: 21316364).

In addition to microtubule nucleation activity, also involved in microtubule bundling and stabilization of existing microtubules, thereby maintaining the integrity of the microtubule network (PubMed: 17105200, PubMed: 17693641, PubMed: 18028908, PubMed: 26289831).

Regulates microtubule dynamics by promoting tubulin acetylation: acts by inhibiting the tubulin deacetylase activity of HDAC6 (PubMed: 20308065, PubMed: 23093407).

Also regulates cell migration: phosphorylation by ROCK1 inhibits interaction with HDAC6, resulting in decreased acetylation of tubulin and increased cell motility (PubMed: 23093407).

Plays a role in cell proliferation by regulating the G1/S-phase transition (PubMed: 23355470).

Involved in astral microtubule organization and mitotic spindle orientation during early stage of mitosis; this process is regulated by phosphorylation by LIMK2 (PubMed: 22328514).