VRK3

VRK3, or vaccinia-related kinase 3, is a protein-coding gene in humans that encodes a member of the vaccinia-related kinase (VRK) family of serine/threonine kinases. VRK family proteins are typically nuclear and participate in signaling pathways that regulate cell cycle, transcription, and chromatin dynamics. VRK3 shares the conserved kinase domain found in the family but is distinguished from VRK1 and VRK2 by reportedly different catalytic properties.

The precise enzymatic activity of VRK3 has been described variably in the literature. Some studies characterize VRK3 as catalytically active, while others describe it as a catalytically inactive regulator or pseudokinase that can modulate the activity of other kinases or signaling components. Because substrates for VRK3 are not yet fully established, its direct catalytic targets remain a topic of investigation. VRK3 is thought to participate in nuclear signaling and may be involved in cellular responses to DNA damage or other stress cues, likely through interactions with other VRK proteins or nuclear factors.

Expression analyses show that VRK3 is expressed in multiple human tissues, with a localization pattern largely in the nucleus consistent with roles in chromatin-related processes. Evolutionarily, VRK3 is conserved among vertebrates, indicating an established regulatory function within this kinase family.

Clinical research on VRK3 is limited. Some studies address potential links to cancer biology and cell cycle regulation, but no definitive diagnostic or therapeutic applications have been established. Overall, VRK3 is a less characterized member of the VRK family, and further research is needed to clarify its enzymatic activity, substrates, regulatory mechanisms, and physiological roles.