Fat cells were incubated with 32Pi for 2 h before the [32P]I-2 was immunoprecipitated, subjected to SDS PAGE, and detected by autoradiography. [32P]I-2 (Mr = 32,000) was not recovered when excess purified I-2 was added with the antiserum or when nonimmune serum was used. Immunoprecipitated I-2 was heat-stable, inhibited phosphatase activity, and could be synergistically phosphorylated by casein kinase II and FA GSK-3. Several times more [32P]phosphoserine than [32P]phosphothreonine was found in I-2 from 32P-labeled cells. Insulin increased the 32P-content of I-2 by as much as 40%, suggesting that phosphorylation of I-2 might be involved in the effect of insulin on stimulating protein dephosphorylation.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Jan 15 1988|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology