Activated CIT phosphorylates MRLCs (mysoin regulatory light chains) at threonine T19 and serine S20 (also labeled in the literature as T18 and S19), and can restore stress fibre assembly when ROCKs are inhibited, although ROCKs play the dominant role in stress fiber formation-related phosphorylation of MRLCs. CIT-mediated phosphorylation of MRLCs may be important during cytokinesis. Unlike ROCKs, CIT does not phosphorylate the myosin binding subunit of the myosin phosphatase complex (Yamashiro et al. 2003).
protein serine/threonine kinase activity of RHOA,RHOB,RHOC,RAC1:GTP:CIT [plasma membrane]