title: Cep-1347 (KT7515), a semisynthetic inhibitor of the mixed lineage kinase family.
abstract: CEP-1347 (KT7515) promotes neuronal survival at dosages that inhibit activation of the c-Jun amino-terminal kinases (JNKs) in primary embryonic cultures and differentiated PC12 cells after trophic withdrawal and in mice treated with 1-methyl-4-phenyl tetrahydropyridine. In an effort to identify molecular target(s) of CEP-1347 in the JNK cascade, JNK1 and known upstream regulators of JNK1 were co-expressed in Cos-7 cells to determine whether CEP-1347 could modulate JNK1 activation. CEP-1347 blocked JNK1 activation induced by members of the mixed lineage kinase (MLK) family (MLK3, MLK2, MLK1, dual leucine zipper kinase, and leucine zipper kinase). The response was selective because CEP-1347 did not inhibit JNK1 activation in cells induced by kinases independent of the MLK cascade. CEP-1347 inhibition of recombinant MLK members in vitro was competitive with ATP, resulting in IC(50) values ranging from 23 to 51 nm, comparable to inhibitory potencies observed in intact cells. In addition, overexpression of MLK3 led to death in Chinese hamster ovary cells, and CEP-1347 blocked this death at doses comparable to those that inhibited MLK3 kinase activity. These results identify MLKs as targets of CEP-1347 in the JNK signaling cascade and demonstrate that CEP-1347 can block MLK-induced cell death.
authors.affiliation: Cephalon Inc., 145 Brandywine Pkwy., West Chester, Pennsylvania 19380, USA. amaroney@cephalon.com
authors.forename: A C
authors.initials: AC
authors.lastname: Maroney
authors.forename: J P
authors.initials: JP
authors.lastname: Finn
authors.forename: T J
authors.initials: TJ
authors.lastname: Connors
authors.forename: J T
authors.initials: JT
authors.lastname: Durkin
authors.forename: T
authors.initials: T
authors.lastname: Angeles
authors.forename: G
authors.initials: G
authors.lastname: Gessner
authors.forename: Z
authors.initials: Z
authors.lastname: Xu
authors.forename: S L
authors.initials: SL
authors.lastname: Meyer
authors.forename: M J
authors.initials: MJ
authors.lastname: Savage
authors.forename: L A
authors.initials: LA
authors.lastname: Greene
authors.forename: R W
authors.initials: RW
authors.lastname: Scott
authors.forename: J L
authors.initials: JL
authors.lastname: Vaught
mesh_terms: D000818:Animals; D016466:CHO Cells; D002227:Carbazoles / Q000494:pharmacology*; D016923:Cell Death; D006224:Cricetinae; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors*; D048055:Mitogen-Activated Protein Kinase 8; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008956:Models, Chemical; D016716:PC12 Cells; D047428:Protein Kinase Inhibitors; D051381:Rats; D000097767:Mitogen-Activated Protein Kinase Kinase Kinase 11
chemical_list: D002227:Carbazoles; D004791:Enzyme Inhibitors; D007211:Indoles; D048031:JNK Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; D048055:Mitogen-Activated Protein Kinase 8; D020928:Mitogen-Activated Protein Kinases; D047428:Protein Kinase Inhibitors; D000097767:Mitogen-Activated Protein Kinase Kinase Kinase 11; C106592:3,9-bis((ethylthio)methyl)-K-252a; C090757:mitogen-activated protein kinase kinase kinase 12