Dataset Information


Activity of protein phosphatases against initiation factor-2 and elongation factor-2.

ABSTRACT: The protein phosphatases active against phosphorylase a, elongation factor-2 (EF-2) and the alpha-subunit of initiation factor-2 (eIF-2) [eIF-2(alpha P)] were studied in extracts of rabbit reticulocytes. Swiss-mouse 3T3 fibroblasts and rat hepatocytes, by use of the specific phosphatase inhibitors okadaic acid and inhibitor proteins-1 and -2. In all three extracts tested, both phosphatase-1 and phosphatase-2A contributed to overall phosphatase activity against phosphorylase and eIF-2(alpha P), but phosphatase-2B and -2C did not. In contrast, only protein phosphatase-2A was active against EF-2. Furthermore, in hepatocytes there was substantial type-2C phosphatase activity against EF-2, but not against phosphorylase or eIF-2 alpha. These findings in cell extracts were borne out by data obtained by studying the activities of purified protein phosphatase-1 and -2A against eIF-2(alpha P) and eIF-2(alpha P) was a moderately good substrate for both enzymes (relative to phosphorylase a). In contrast, EF-2 was a very poor substrate for protein phosphatase-1, but was dephosphorylated faster than phosphorylase a by protein phosphatase-2A. The implications of these findings for the control of translation and their relationships to previous work are discussed.


PROVIDER: S-EPMC1149673 | BioStudies | 1990-01-01

SECONDARY ACCESSION(S): 10.1042/bj2720175

REPOSITORIES: biostudies

Similar Datasets

1989-01-01 | S-EPMC1133265 | BioStudies
1000-01-01 | S-EPMC358930 | BioStudies
1988-01-01 | S-EPMC1135400 | BioStudies
1985-01-01 | S-EPMC1144642 | BioStudies
1994-01-01 | S-EPMC1138030 | BioStudies
1977-01-01 | S-EPMC1164616 | BioStudies
1993-01-01 | S-EPMC1134912 | BioStudies
1989-01-01 | S-EPMC1133313 | BioStudies
1995-01-01 | S-EPMC1136307 | BioStudies
1000-01-01 | S-EPMC3838779 | BioStudies