title: Differential role of the JNK and p38 MAPK pathway in c-Myc- and s-Myc-mediated apoptosis.
abstract: The s-Myc is similar to c-Myc in its ability to induce apoptosis requiring caspase activation. However, s-Myc is distinct from c-Myc in that it has activity to suppress tumor growth and does not require wild-type p53 to induce apoptosis. These facts suggest differential regulation between s-Myc and c-Myc. Here we showed that s-Myc-mediated apoptosis triggered by UV was not inhibited by the inactive form mutant JNK (APF), though c-Myc-mediated apoptosis was. Moreover, we found that JNK did not affect the transactivation activity of s-Myc, but stimulated that of c-Myc. In contrast, both Myc-mediated apoptosis and caspase-3-like protease activation were suppressed by kinase-negative MKK6 and an inactive form mutant p38(AGF). Our results indicate that s-Myc does not require the JNK signaling unlike c-Myc during UV-triggered apoptosis, but the MKK6/p38MAPK pathway might regulate common apoptotic machinery for both s-Myc and c-Myc upstream of caspase.
authors.affiliation: Biophysics Division, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo, 104-0045, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Noguchi
authors.forename: H
authors.initials: H
authors.lastname: Yamana
authors.forename: C
authors.initials: C
authors.lastname: Kitanaka
authors.forename: T
authors.initials: T
authors.lastname: Mochizuki
authors.forename: A
authors.initials: A
authors.lastname: Kokubu
authors.forename: Y
authors.initials: Y
authors.lastname: Kuchino
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology* / Q000528:radiation effects; D019556:COS Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D017930:Genes, Reporter; D006367:HeLa Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D007700:Kinetics; D048669:MAP Kinase Kinase 6; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D014466:Ultraviolet Rays; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D011994:Recombinant Proteins; D015500:Chloramphenicol O-Acetyltransferase; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048669:MAP Kinase Kinase 6; C482566:MAP2K6 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D020169:Caspases