Mouse anti-VRK1. Monoclonal antibody specific to Human VRK1. This antibody is validated for use Western Blot, and Immunoprecipitation. VRK1 is encoded by VRK1 Gene. Mouse anti-VRK1. Monoclonal antibody specific to Human VRK1. This antibody is validated for use Western Blot, and Immunoprecipitation. VRK1 is encoded by VRK1 Gene. Vaccinia-Related Kinase (VRK) proteins are a new family with three members in the human kinome. VRK1 is a serine⁄threonine kinase which phosphorylates transcription factors related to stress responses, such as p53. VRK1 phosphorylates human p53 in threonine 18 leading to its accumulation. VRK1 is also autophosphorylated at various serine and threonine residues. However, this does not impair its ability to phosphorylate p53. There also seems to be an autoregulatory loop between p53 and its stabilizing VRK1 since inverse correlation between VRK1 and p53 levels are observed in several cell lines. VRK1 also phosphorylates c-Jun at serines 63 and 73, inducing the stabilization and accumulation of the c-Jun protein. Similarly, threonine 73 of ATF2 is the target residue for VRK-1 phosphorylation. Recent evidence also shows that VRK1 is a novel mitotic histone H3 kinase in mammals. Elimination of VRK1 by siRNA results in a G1 block in cell division, and in loss of phosphorylated-Rb, cyclin D1, and other proliferation markers. These results indicate that VRK1 plays a role in normal cell proliferation and division, and might be a novel target for development of inhibitors of cellular proliferation.