Kinases like Protein kinase C delta (PKC-delta) and Calcium/calmodulin-dependent protein kinase II (CaMK II ) can phosphorylate STAT1 at serine 727 (S727). This phosphorylation is not required for STAT1 homodimer formation, nuclear translocation and DNA binding. However, it is essential for the full transcriptional activation of STAT1.
Darnell JE, Jr,
protein kinase C activity of CaMKII and PKC-delta [cytosol]