IL-2 induces transient and specific decrease in cytosolic protein phosphatase PP1 activity in murine T cell lines.
In the IL-2-dependent murine cytotoxic T cell line CTLL-2, IL-2 induced a rapid and transient decrease in Co(2+)-trypsin-treated activity of protein phosphatase PP1. The PP1 activity declined to a minimum level, being 70% of control value, in 20 min after the addition of IL-2 but recovered to the control level within 45 min. The decrease of PP1 activity was dependent on IL-2 concentration and occurred specifically in cytosolic fraction. Similar alteration was observed in IL-2 sensitive murine T-lymphoblasts. Neither activity of protein phosphatase PP2A nor PP2C showed alteration during the IL-2 stimulation. These results suggest that PP1 plays an important role in early events of the intracellular growth signaling from the IL-2 receptor.
Section of Biochemistry, Hokkaido University, Japan.
S
S
Matsuzawa
A
A
Matsuda
Y
Y
Mizuno
K
K
Kikuchi
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003600:Cytosol / Q000201:enzymology; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000201:enzymology*; D013997:Time Factors; D014357:Trypsin / Q000494:pharmacology
D007376:Interleukin-2; D007527:Isoenzymes; D011994:Recombinant Proteins; D010749:Phosphoprotein Phosphatases; D014357:Trypsin