Tumor necrosis factor receptor I (TNFRI) activation triggers a cytotoxic response in a wide variety of cell types. The TNF mediated cytotoxicity is dependent upon a region of the TNFRI designated the "death domain" that is located in the cytoplasmic tail. Mouse pelle-like kinase (mPLK) is a novel protein kinase with 81% sequence identity to the human interleukin1 receptor associated kinase (IRAK) that is capable of autophosphorylation and phosphoryiation of IkBa. A region homologous to the TNFRI death domain is present at the NH2 terminus of mPLK and IRAK. Since the death domain has been implicated in the binding of several proteins to the TNFRI, we set out to determine whether mPLK and the TNFRI could be found physically associated in vivo. When Hela cell lysates were immunoprecipitated with anti-mPLK antisera the complexes contained not only mPLK but also the TNFRI. Similar results were obtained when immunocomplexes were formed using anti-TNFRl antisera. Interestingly, we detected the 80 kDa form of mPLK in association with the TNFRI; whereas, the 100 kDa form of mPLK was shown to be associated with the type I interleukin-1 (IL-1) receptor. The mPLK-TNFRI interaction suggests TNF and IL-1 may both signal through mPLK. An understanding of how the different isoforms of mPLK interact with IL-1RI and TNFRI may provide insight into how a common mediator may be recruited by distinct inflammatory cytokines.
|Original language||English (US)|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Molecular Biology