DEVELOPMENTAL AND TISSUE-SPECIFIC EXPRESSION OF MOUSE PELLE-LIKE PROTEIN-KINASE

The NF-kappa B/c-Rel proteins are a family of evolutionarily conserved transcription factors activated during development that in the adult, mediate many processes including the immune response, A high degree o f sequence similarity is shared between the NF-kappa B/c-Rel family of transcription factors and the Drosophila Dorsal protein as well as be tween its cytoplasmic inhibitor, I kappa B alpha and the Drosophila Ca ctus protein, Genetic analyses of Dorsal have defined components of a signaling pathway for Dorsal activation, including a serine/threonine kinase, Pelle, placed upstream of Dorsal and Cactus, We demonstrate th at this pathway is likely to be conserved in mammals by the isolation of a cDNA that encodes a novel mouse protein highly related to Pelle, mPLK (mouse Pelle-like protein kinase), Expression of mPLK mRNA is dev elopmentally regulated in the mouse and in adult tissue mPLK expressio n is greatest in the liver, a tissue that expresses a high level of NF -kappa B, Recombinant mPLK produced in bacteria is a protein kinase ca pable of autophosphorylating and phosphorylating I kappa B alpha.