| First Author | Ganiatsas S | Year | 1998 |
| Journal | Proc Natl Acad Sci U S A | Volume | 95 |
| Issue | 12 | Pages | 6881-6 |
| PubMed ID | 9618507 | Mgi Jnum | J:48772 |
| Mgi Id | MGI:1274987 | Doi | 10.1073/pnas.95.12.6881 |
| Citation | Ganiatsas S, et al. (1998) SEK1 deficiency reveals mitogen-activated protein kinase cascade crossregulation and leads to abnormal hepatogenesis. Proc Natl Acad Sci U S A 95(12):6881-6 |
| abstractText | SEK1 (MKK4/JNKK) is a mitogen-activated protein kinase activator that has been shown to participate in vitro in two stress-activated cascades terminating with the SAPK and p38 kinases. To define the role of SEK1 in vivo, we studied stress-induced signaling in SEK1(-/-) embryonic stem and fibroblast cells and evaluated the phenotype of SEK1(-/-) mouse embryos during development. Studies of SEK1(-/-) embryonic stem cells demonstrated defects in stimulated SAPK phosphorylation but not in the phosphorylation of p38 kinase. In contrast, SEK1(-/-) fibroblasts exhibited defects in both SAPK and p38 phosphorylation, demonstrating that crosstalk exists between the stress-activated cascades. Tumor necrosis factor alpha and interleukin 1 stimulation of both stress-activated cascades are severely affected in the SEK1(-/-) fibroblast cells. SEK1 deficiency leads to embryonic lethality after embryonic day 12.5 and is associated with abnormal liver development. This phenotype is similar to c-jun null mouse embryos and suggests that SEK1 is required for phosphorylation and activation of c-jun during the organo-genesis of the liver. |
