p38, a member of the mitogen-activated
protein kinase (MAPK) superfamily,
is activated in response to a variety of cellular stresses and ligands. Since the genome of the nematode C. elegans has been sequenced, we sought to identify and
characterize the nematode homolog of mammalian p38. By sequence analysis and
RT-PCR, we isolated cDNAs encoding three kinases, PMK-1, PMK-2, and PMK-3, which we call p38 map kinases due to their high sequence identity with p38. The
three genes are contiguous on chromosome IV and comprise an operon.
By use of a GFP reporter, we found that the promoter of the pmks
is active throughout the intestine. An active form of MAPK/ERK kinase 6 (MEK6) phosphorylated
and activated recombinant PMK-1 and PMK-2 in vitro. PMK-1 and PMK-2 phosphorylated activating transcription factor-2 (ATF-2),
indicating an activity similar to mammalian p38. When transfected into mammalian cells, these kinases,
like p38, are stimulated by osmotic stresses. Copyright
2001 Academic Press.
PMID: 12662322 [PubMed - indexed for MEDLINE]