Abstract
A cDNA was cloned and expressed that encodes human stress-activated protein kinase kinase-4 (SKK4), a novel MAP kinase kinase family member whose mRNA is widely expressed in human tissues. SKK4 activated SAPK1/JNK in vitro, but not SAPK2a/p38, SAPK2b/p38β, SAPK3/ERK6 or SAPK4. It appears to be the mammalian homologue of HEP, an activator of SAPK1/JNK in Drosophila. In human epithelial KB cells SKK4 and SKK1/MKK4 (another activator of SAPK1/ JNK) were both activated by stressful stimuli, but only SKK4 was activated by proinflammatory cytokines. The identification of SKK4 explains why the major SAPK1/JNK activator detected in many mammalian cell extracts is chromatographically separable from SKK1/MKK4.
Original language | English |
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Pages (from-to) | 153-158 |
Number of pages | 6 |
Journal | FEBS Letters |
Volume | 414 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Sept 1997 |
Keywords
- Cytokine
- JNK
- MAP kinase
- p38
- SAPK
- Stress
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology