1. To further test the specificity of the polypeptides detected in the crude extract we utilised the LZ competition assay. 2. The two c-Jun derivatives were then tested for an ability to be phosphorylated by kinases present in a crude HeLa cell nuclear extract. 3. Taken together, these data indicate that a DNA-dependent kinase present in crude HeLa nuclear extracts specifically phosphorylates the bZIP region of c-Jun. 4. This protein was then purified and tested for an ability to be phosphorylated in a crude HeLa cell nuclear extract. 5. Fourth, under our assay conditions in the presence of DNA, the dominant c-Jun kinase in unfractionated crude nuclear extracts is the DNA-PK. 6. She warned against anyone trying to use a crude extract from creosote for self-treatment, because of possible toxicity. |