VRK1

This gene encodes a member of the vaccinia-related kinase (VRK) family of serine/threonine protein kinases. This gene is widely expressed in human tissues and has increased expression in actively dividing cells, such as those in testis, thymus, fetal liver, and carcinomas. Its protein localizes to the nucleus and has been shown to promote the stability and nuclear accumulation of a transcriptionally active p53 molecule and, in vitro, to phosphorylate Thr18 of p53 and reduce p53 ubiquitination. This gene, therefore, may regulate cell proliferation. This protein also phosphorylates histone, casein, and the transcription factors ATF2 (activating transcription factor 2) and c-JUN. [provided by RefSeq, Jul 2008]

Vaccinia Related Kinase 1

Serine/threonine kinase involved in cell cycle, nuclear condensation and transcription regulation (PubMed:14645249, PubMed:18617507, PubMed:19103756).
Involved in Golgi disassembly during the cell cycle: following phosphorylation by PLK3 during mitosis, required to induce Golgi fragmentation (PubMed:19103756).
Phosphorylates 'Thr-18' of p53/TP53 and may thereby prevent the interaction between p53/TP53 and MDM2 (PubMed:10951572).
Phosphorylates KAT5 in response to DNA damage, promoting KAT5 association with chromatin and histone acetyltransferase activity (PubMed:33076429).
Phosphorylates BANF1: disrupts its ability to bind DNA, reduces its binding to LEM domain-containing proteins and causes its relocalization from the nucleus to the cytoplasm (PubMed:16495336).
Phosphorylates ATF2 which activates its transcriptional activity (PubMed:15105425).

Biological Process cell division Source:UniProtKB-KW
Biological Process cellular response to DNA damage stimulus Source:UniProtKB1 Publication
Biological Process Golgi disassembly Source:UniProtKB1 Publication
Biological Process mitotic nuclear membrane disassembly Source:Reactome
Biological Process peptidyl-serine phosphorylation Source:GO_Central1 Publication
Biological Process positive regulation of protein localization to chromatin Source:UniProtKB1 Publication
Biological Process protein autophosphorylation Source:UniProtKB2 Publications
Biological Process protein phosphorylation Source:ProtInc1 Publication
Biological Process signal transduction Source:GO_Central1 Publication

Nucleus
Cytoplasm
Dispersed throughout the cell but not located on mitotic spindle or chromatids during mitosis.

Pontocerebellar hypoplasia 1A (PCH1A):
A disorder characterized by an abnormally small cerebellum and brainstem, central and peripheral motor dysfunction from birth, gliosis and spinal cord anterior horn cells degeneration resembling infantile spinal muscular atrophy. Additional features include muscle hypotonia, congenital contractures and respiratory insufficiency that is evident at birth.

Autophosphorylated at various serine and threonine residues (PubMed:11883897, PubMed:14645249, PubMed:19103756, PubMed:21543316).
Autophosphorylation does not impair its ability to phosphorylate p53/TP53 (PubMed:11883897).
Phosphorylation by PLK3 leads to induction of Golgi fragmentation during mitosis (PubMed:19103756).