VRK1
VRK1 (VRK serine/threonine kinase 1, previously vaccinia related kinase 1) is a nuclear serine/threonine kinase that regulates the cell cycle, chromatin organisation, transcription and the DNA damage response. It belongs to the VRK subfamily of the CK1 kinase group. Browse Assay Genie's current range of VRK1 research reagents below, or read on for the biology behind the target.
VRK1 is a serine/threonine kinase involved in key cellular processes, including cell cycle control, nuclear condensation, transcription regulation and the DNA damage response. It shapes chromatin organisation and remodelling by phosphorylating histone H3 on Thr-4 and histone H2AX. It also phosphorylates KAT5 after DNA damage, which promotes KAT5 association with chromatin and its histone acetyltransferase activity.
Among its substrates, VRK1 phosphorylates p53 on Thr-18, which prevents p53 from interacting with MDM2. In vitro, this reduces p53 ubiquitination and supports the stability and nuclear accumulation of transcriptionally active p53. VRK1 also phosphorylates TP53BP1, BANF1, casein, and the transcription factors ATF2 and c-JUN. Phosphorylation of ATF2 activates its transcriptional activity. Phosphorylation of BANF1 disrupts its DNA binding, reduces its binding to LEM domain-containing proteins and moves it from the nucleus to the cytoplasm. Other roles include Cajal body assembly, through COIL phosphorylation and control of coilin degradation, and Golgi fragmentation during mitosis after phosphorylation by PLK3. In neural tissue, VRK1 is involved in the cell cycle progression of neural progenitors, is required for cortical neuronal migration, and contributes to neurite elongation and branching in motor neurons.
The VRK1 gene is widely expressed in human tissues. Expression is higher in actively dividing cells, such as those in testis, thymus, foetal liver and carcinomas, so the kinase may regulate cell proliferation. The protein is mainly nuclear and also found in the cytoplasm and in Cajal bodies. It belongs to the VRK family, a subfamily within the CK1 Ser/Thr protein kinase group. The mouse ortholog is Vrk1.
VRK1 expression is higher in actively dividing cells and carcinomas, and the kinase may regulate cell proliferation.
VRK1 phosphorylates KAT5, histone H2AX and TP53BP1, linking the kinase to chromatin remodelling after DNA damage.
Phosphorylation of p53 on Thr-18 blocks MDM2 interaction, supporting p53 stability and nuclear accumulation.
VRK1 supports neural progenitor cycling, cortical neuronal migration, and neurite elongation and branching in motor neurons.
VRK1 is a serine/threonine kinase that regulates the cell cycle, nuclear condensation, transcription and the DNA damage response. It phosphorylates histone H3, H2AX, KAT5, p53, ATF2 and c-JUN, and it is needed for Cajal body assembly and for Golgi fragmentation during mitosis.
VRK1 stands for VRK serine/threonine kinase 1. Its previous HGNC name was vaccinia related kinase 1. UniProt lists the protein as serine/threonine-protein kinase VRK1. No alternative gene symbols are recorded in the HGNC data supplied.
VRK1 has a mouse ortholog, Vrk1. In humans the gene is widely expressed, with increased expression in dividing cells such as those in testis, thymus, foetal liver and carcinomas. Check the datasheet of any product for its validated reactivity.
Substrates and regulators of VRK1, including p53 pathway proteins, transcription factors and DNA damage response factors.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q99986; product specifications from Assay Genie datasheets.