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Description |
PRAK
(p38-regulated /activated kinase), also referred to as mitogen-activated
protein kinase (MAPK)-activated protein kinase (MAPKAPK)-5, is
an ubiquitously expressed serine/threonine kinase regulated by
p38α and p38β MAP kinases. Activated JNK, p38γ or p38δ are
unable to induce phosphorylation of PRAK in vitro.
Phosphorylation of PRAK occurs in vivo in response to p38
activation by stress-related extracellular stimuli including UV
light, oxidation and proinflammatory cytokines. Two other
substrates for p38, MAPKAPK-2 and MAPKAPK-3/3pK, share
approximately 45% sequence homology with PRAK including the
phosphorylation motif recognized by p38, Lys-X-Thr-Pro.
Activated PRAK has been shown to specifically phosphorylate HSP
27 in vitro, suggesting that the protein may play a role in
stress-induced small heat shock protein phosphorylation in vivo. |
