In vivo incorporation of 14C-tyrosine into the C-terminal position of the -subunit of tubulin

ARGARAÑA C.E.; ARCE C.A,; BARRA H.S,; CAPUTTO R.

ELSEVIER SCIENCE INC

Año: 1977 vol. 180 p. 264 - 264

n vitro incorporation of 14C-ltyrosine into the C-terminal position of the alpha subunit of tubulin was not affected by 4 mM cycloheximide. This inhibitor of protein synthesis was used for in vivo experiments. The in vivo incorporation of 14C-tyrosine into soluble brain protein of cycloheximide-treated rats was 10% of that of untreated rats. Treatment with vinblastine sulfate of the soluble brain protein showed that the incorporation of 14C-tyrosine into tubulin was higher in cycloheximide-treated than in untreated rats with respect to the incorporation into the total soluble protein. In the case of cycloheximide-treated rats, about 60% of the radioactivity incorporated into protein was released by the action of carboxypeptidase A, whereas 10% was liberated from the protein of untreated rats. The radioactive compound released by the action of carboxypeptidase A was identified as 14C-tyrosine. The alpha and beta subunits of tubulin from animals that received 14C-tyrosine were separated