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A 14 kDa release factor is involved in GTP‐dependent β‐tubulin folding
Author(s) -
Campo Rafael,
Fontalba Ana,
Sanchez Luis M.,
Zabala Juan C.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)01036-6
Subject(s) - tubulin , gtp' , dimer , monomer , size exclusion chromatography , chemistry , biochemistry , folding (dsp implementation) , chaperone (clinical) , biophysics , protein folding , molecular mass , gel electrophoresis , microbiology and biotechnology , biology , microtubule , enzyme , polymer , organic chemistry , medicine , engineering , pathology , electrical engineering
The tubulin folding pathway is a model system to understand protein folding in the cell. It involves the interaction of several chaperones, including TCP‐1 and other as yet uncharacterized factors. Release of tubulin monomers from folding intermediates (C 900 and C 300 ) and their incorporation into tubulin dimers is dependent on GTP hydrolysis, magnesium ions and release factors. In this work, we have purified to homogeneity the protein factor responsible for the release of β‐tubulin monomers from C 300 complexes. It has an apparent molecular mass of 14 kDa (p14) as judged by SDS electrophoresis. The protein behaved as a dimer of about 28 kDa when analyzed by gel filtration chromatography. Furthermore, the p14‐dependent release of β‐tubulin monomers from C 300 complexes takes place in the presence of GTP. These results suggest that p14 is a new chaperone that assists in tubulin folding by facilitating the acquisition of the native conformation.