A Caenorhabditis elegans MAP kinase kinase, MEK-1, is involved in stress responses.
The c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase (MAPK) family, was shown to be involved in the response to various stresses in cultured cells. However, there is little in vivo evidence indicating a role for a JNK pathway in the stress response of an organism. We identified the Caenorhabditis elegans mek-1 gene, which encodes a 347 amino acid protein highly homologous to mammalian MKK7, an activator of JNK. Mek-1 reporter fusion proteins are expressed in pharyngeal muscle, uterus, a portion of intestine, and neurons. A mek-1 deletion mutant is hypersensitive to copper and cadmium ions and to starvation. A wild-type mek-1 transgene rescued the hypersensitivity to the metal ions. Double mutants of mek-1 with an eat-5, eat-11 or eat-18 mutation, which are characterized by a limited feeding defect, showed distinct growth defects under normal conditions. Expression of an activated form of MEK-1 in the whole animal or specifically in the pharynx inhibited pharyngeal pumping. These results suggest a role for mek-1 in stress responses, with a focus in the pharynx and/or intestine.
Koga
M
M
Department of Biology, Faculty of Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan.
Zwaal
R
R
Guan
K L
KL
Avery
L
L
Ohshima
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D002104:Cadmium / Q000494:pharmacology; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D003300:Copper / Q000494:pharmacology; D005260:Female; D005508:Food Deprivation; D018869:Heat-Shock Response; D015801:Helminth Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D048688:MAP Kinase Kinase 7; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics; D008969:Molecular Sequence Data; D009068:Movement; D010058:Oviposition; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D016415:Sequence Alignment; D017384:Sequence Deletion
D015801:Helminth Proteins; D002104:Cadmium; D003300:Copper; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D048688:MAP Kinase Kinase 7; D020929:Mitogen-Activated Protein Kinase Kinases