Interleukin 1 signal transduction.

Interleukin 1 signals through an 80kDa receptor to change protein kinase activity in fibroblasts. Two increases in protein phosphorylation have been identified: the EGF receptor and the small heat shock protein (hsp 27). Both involve serine and are similarly transient (maximal 5-15 minutes). The kinase activity differs from PKA or C. Hsp 27 can be used for its assay in extracts of stimulated cells.