Pathway leading to correctly folded beta-tubulin

Cell. 1996 Jul 26;86(2):287-96. doi: 10.1016/s0092-8674(00)80100-2.


We describe the complete beta-tubulin folding pathway. Folding intermediates produced via ATP-dependent interaction with cytosolic chaperonin undergo a sequence of interactions with four proteins (cofactors A, D, E, and C). The postchaperonin steps in the reaction cascade do not depend on ATP or GTP hydrolysis, although GTP plays a structural role in tubulin folding. Cofactors A and D function by capturing and stabilizing beta-tubulin in a quasi-native conformation. Cofactor E binds to the cofactor D-beta-tubulin complex; interaction with cofactor C then causes the release of beta-tubulin polypeptides that are committed to the native state. Sequence analysis identifies yeast homologs of cofactors D (cin1) and E (pac2), characterized by mutations that affect microtubule function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cattle
  • Cell Extracts / chemistry
  • Chaperonins / physiology
  • Endopeptidases
  • Male
  • Molecular Sequence Data
  • Protein Folding
  • Proteins / genetics
  • Proteins / isolation & purification
  • Proteins / metabolism
  • Rabbits
  • Sensitivity and Specificity
  • Sequence Homology, Amino Acid
  • Tubulin / analysis
  • Tubulin / chemistry*


  • Cell Extracts
  • Proteins
  • Tubulin
  • Endopeptidases
  • Chaperonins

Associated data

  • GENBANK/U61232
  • GENBANK/U61233
  • GENBANK/U61234