RRC ID 35944
著者 Wada T, Nakagawa K, Watanabe T, Nishitai G, Seo J, Kishimoto H, Kitagawa D, Sasaki T, Penninger JM, Nishina H, Katada T.
タイトル Impaired synergistic activation of stress-activated protein kinase SAPK/JNK in mouse embryonic stem cells lacking SEK1/MKK4: different contribution of SEK2/MKK7 isoforms to the synergistic activation.
ジャーナル J Biol Chem
Abstract Stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK), which is a member of the mitogen-activated protein kinase (MAPK) family, plays an important role in a stress-induced signaling cascade. SAPK/JNK activation requires the phosphorylation of Thr and Tyr residues in its Thr-Pro-Tyr motif, and SEK1 (MKK4) and MKK7 (SEK2) have been identified as the upstream MAPK kinases. Here we examined the activation and phosphorylation sites of SAPK/JNK and differentiated the contribution of SEK1 and MKK7alpha1, -gamma1, and -gamma2 isoforms to the MAPK activation. In SEK1-deficient mouse embryonic stem cells, stress-induced SAPK/JNK activation was markedly impaired, and this defect was accompanied with a decreased level of the Tyr phosphorylation. Analysis in HeLa cells co-transfected with the two MAPK kinases revealed that the Thr and Tyr of SAPK/JNK were independently phosphorylated in response to heat shock by MKK7gamma1 and SEK1, respectively. However, MKK7alpha1 failed to phosphorylate the Thr of SAPK/JNK unless its Tyr residue was phosphorylated by SEK1. In contrast, MKK7gamma2 had the ability to phosphorylate both Thr and Tyr residues. In all cases, the dual phosphorylation of the Thr and Tyr residues was essentially required for the full activation of SAPK/JNK. These data provide the first evidence that synergistic activation of SAPK/JNK requires both phosphorylation at the Thr and Tyr residues in living cells and that the preference for the Thr and Tyr phosphorylation was different among the members of MAPK kinases.
巻・号 276(33)
ページ 30892-7
公開日 2001-8-17
DOI 10.1074/jbc.M011780200
PII S0021-9258(20)80235-X
PMID 11418587
MeSH Animals Cell Line Embryo, Mammalian / enzymology* Enzyme Activation HeLa Cells Humans JNK Mitogen-Activated Protein Kinases MAP Kinase Kinase 4* MAP Kinase Kinase 7 Mice Mitogen-Activated Protein Kinase Kinases / physiology* Mitogen-Activated Protein Kinases / physiology* Phosphorylation Protein Isoforms Rats Stem Cells / enzymology*
IF 4.238
引用数 54
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
遺伝子材料 MKK7 (RDB03430) SEK1 (RDB03429).