XB-ART-40716Mol Cell Biol February 1, 2010; 30 (3): 675-83.
Nemo-like kinase, an essential effector of anterior formation, functions downstream of p38 mitogen-activated protein kinase.
Nemo-like kinase (NLK) is known to function as a mitogen-activated protein kinase (MAPK)-like kinase. However, the upstream molecules and molecular mechanisms that regulate NLK activity remain unclear. In the present study, we identified p38 MAPK as an upstream kinase and activator of NLK. p38 regulates the function of NLK via phosphorylation, and this modification can be abrogated by depletion of endogenous p38. In Xenopus laevis embryos, depletion of either p38beta or NLK by antisense morpholino oligonucleotides results in a severe defect in anterior development and impaired expression of endogenous anterior markers. It is notable that morphants of Xenopus p38alpha, another isoform of the p38 MAPK family, exhibited no obvious defects in anterior development. Defects in head formation or in the expression of anterior marker genes caused by suppression of endogenous p38beta expression could be rescued by expression of wild-type NLK but not by expression of mutant NLK lacking the p38beta phosphorylation site. In contrast, defects in head formation or in the expression of anterior marker genes caused by suppression of endogenous NLK expression could not be rescued by expression of p38. These results provide the first evidence that p38 specifically regulates NLK function, which is required for anterior formation in Xenopus development.
PubMed ID: 19933839
PMC ID: PMC2812222
Article link: Mol Cell Biol
Genes referenced: cav3.2 grap2 mapk1 mapk11 mapk14 nlk nlk.2
Morpholinos: mapk11 MO1 mapk14 MO1 nlk MO1 nlk.2 MO1
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References [+] :
Alonso, Differential activation of p38 mitogen-activated protein kinase isoforms depending on signal strength. 2001, Pubmed, Xenbase