VRK2s

VRK2s are the protein products of the VRK2 gene, a member of the vaccinia-related kinase family. Like other VRKs, VRK2s are serine/threonine kinases that transfer phosphate from ATP to specific substrate proteins, thereby modulating signaling pathways that govern cell cycle progression, transcription, and stress responses. In humans, VRK2 exists mainly as two isoforms produced by alternative splicing: VRK2A and VRK2B. VRK2A is commonly described as membrane-associated, while VRK2B is more soluble and can localize to the nucleus, reflecting potential specialization of function between the isoforms.

VRK2 proteins have been reported to participate in signaling networks that intersect with p53, MAPK, and other stress-related pathways, and to influence cellular responses to DNA damage and metabolic stress. They may regulate the activity of transcription factors and other kinases through phosphorylation, either directly or via regulatory complexes. The precise substrates and physiological roles of VRK2s vary by tissue context and developmental stage, and may be modulated by subcellular localization.

Expression of VRK2 transcripts and protein has been detected in a broad range of tissues, with some reports noting higher levels in brain tissue and certain immune cell types. Because VRK2 and related VRKs can affect cell proliferation and survival, dysregulation of VRK2 signaling has been studied in the context of cancer and neural development, though findings are not yet conclusive.

In summary, VRK2s are active kinases within the vaccinia-related kinase family, encoded by VRK2, with two main isoforms that differ in localization and possibly function, contributing to diverse signaling processes that coordinate cell growth, stress responses, and transcriptional control.