mixing experiments between hela and mrc5 cell fractions after partial purification on columns of poly ( i ) .poly ( c ) -sepharose , showed that the absence of detection of the protein kinase activity in mrc5 cells can not be attributed to the presence of phosphatases or other inhibitors of phosphorylation in control or interferon-treated mrc5 cell extracts .
C0033640
protein
C0031715
phosphorylation