Tubulin polymerization-promoting protein - O94811 (TPPP_HUMAN)


Protein Feature View of PDB entries mapped to a UniProtKB sequence  

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). UniProt
Catalytic Activity
GTP + H2O = GDP + H+ + phosphate UniProt
Pathway Maps
      ESCHER  BiGG
Subunit Structure
Homodimer (PubMed:17693641, PubMed:22484033, PubMed:26289831). Binds tubulin; binding is inhibited by GTP (PubMed:17105200, PubMed:26289831). Interacts with MAPK1 (By similarity). Interacts with GAPDH; the interaction is direct (By similarity). Interacts with LIMK1 (via the PDZ domain); the interaction is direct (PubMed:18028908, PubMed:22328514). Interacts with LIMK2 (PubMed:22328514). Interacts with HDAC6; thereby inhibiting the tubulin deacetylase activity of HDAC6 (PubMed:20308065, PubMed:23093407). Interacts with aggregated SNCA; may have a pro-aggregatory role in synucleinopathies (PubMed:15590652, PubMed:17027006). Interacts with DYNLL1 (PubMed:31505170). UniProt
Most of the protein is composed of disordered regions (PubMed:21316364). Zinc-binding induces structural rearrangement by promoting molten globule state formation (PubMed:21995432). UniProt
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Data in green originates from UniProtKB  
Variation data (sourced from UniProt) shows non-genetic variation from the ExPASy   and dbSNP   websites.
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in purple originates from Phosphosite  .
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
  • Red: hydrophobic
  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
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Validation Track

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Data in red indicates combined ranges of Homology Models from the SWISS-MODEL Repository  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
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