Artículos
Título:
Inhibitors of protein phosphatase 1 and 2A decrease the level of tubulin carboxypeptidase activity associated with microtubules.
Autor/es:
CONTÍN MA, PURRO SA, BISIG CG, BARRA HS, ARCE CA.
Revista:
EUROPEAN JOURNAL OF BIOCHEMISTRY
Referencias:
Año: 2003 vol. DIC p. 4921 - 4921
Resumen:
he association of tubulin carboxypeptidase with microtubules may be
involved in the determination of the tyrosination state of the
microtubules, i.e. their proportion of tyrosinated vs. nontyrosinated
tubulin. We investigated the role of protein phosphatases in the
association of carboxypeptidase with microtubules in COS cells. Okadaic
acid and other PP1/PP2A inhibitors, when added to culture medium before
isolation of the cytoskeletal fraction, produced near depletion of the
carboxypeptidase activity associated with microtubules. Isolation of
the native assembled and nonassembled tubulin fractions from cells
treated and not treated with okadaic acid, and subsequent in vitro
assay of the carboxypeptidase activity, revealed that the enzyme was
dissociated from microtubules by okadaic acid treatment and recovered
in the soluble fraction. There was no effect by nor-okadaone (an
inactive okadaic acid analogue) or inhibitors of PP2B and of tyrosine
phosphatases which do not a