Treatment of cells with interferon (IFN)-α caused phosphorylation and activation of cytosolic phospholipase A2 (cPLA2). The protein tyrosine kinase Jak1 was found to be necessary for the activation of cPLA2. Jak1 could be co-immunoprecipitated with cPLA2 from cell extracts, indicating that a close physical interaction occurs between these two proteins. The induction of IFN-stimulated gene factor three (ISGF3) by IFN-α, is blocked by cPLA2 inhibitors in cell cultures and in cell-free reconstituted systems. However, these inhibitors do not block IFN-α- or γ-induced binding of STAT1 to the inverted repeat (IR) element of the IFN regulatory factor 1 (IRF-1) gene. Thus, cPLA2 activation occurs as an early event in the IFN-α response and is selectively involved in ISGF3-dependent gene activation.
|Number of pages||6|
|Journal||The EMBO Journal|
|Publication status||Published - 1 Apr 1996|
- Phospholipase A
- Signal transduction