function:Binds to alpha-tubulin folding intermediates after their interaction with cytosolic chaperonin in the pathway leading from newly synthesized tubulin to properly folded heterodimer. Involved in regulation of tubulin heterodimer dissociation. May function as a negative regulator of axonal growth.,PTM:Phosphorylation by PAK1 is required for normal function. Phosphorylated upon DNA damage, probably by ATM or ATR.,PTM:Ubiquitinated in the presence of GAN which targets it for degradation by the proteasome.,similarity:Belongs to the TBCB family.,similarity:Contains 1 CAP-Gly domain.,subcellular location:Colocalizes with microtubules. In differentiated neurons, located in the cytoplasm. In differentiating neurons, accumulates at the growth cone.,subunit:Supercomplex made of cofactors A to E. Cofactors A and D function by capturing and stabilizing tubulin in a quasi-native conformation. Cofactor E binds to the cofactor D-tubulin complex; interaction with cofactor C then causes the release of tubulin polypeptides that are committed to the native state. Cofactors B and E can form a heterodimer which binds to alpha-tubulin and enhances their ability to dissociate tubulin heterodimers. Binds to GAN.,tissue specificity:Found in most tissues.,