Requirement for protein kinase R in interleukin-1alpha-stimulated effects in cartilage.

Interleukin-1 (IL-1) has pleiotropic effects in cartilage. The interferon-induced, double stranded RNA-activated protein kinase PKR that phosphorylates eukaryotic initiation factor 2 (eIF2) alpha has been implicated in cytokine effects in chondrocytes. A compound was recently identified that potently suppresses PKR autophosphorylation (IC50 approximately 200 etaM) and partially restores PKR-inhibited translation in a cell-free system with significant effect in the nanomolar range.