serine/threonine protein kinase VRK1; vaccinia-related kinase 1 (VRK1)

Function

• serine/threonine protein kinase
• phosphorylates Thr-18 of p53/TP53, thus prevent interaction between p53/TP53 & MDM2
• phosphorylates casein & histone H3
• phosphorylates BANF1
  • disrupts its ability to bind DNA
  • reduces its binding to LEM domain-containing proteins
  • causes its relocalization from nucleus to cytoplasm
• active in presence of Mn+2, Mg+2 & Zn+2
  • higher affinity for Mn+2 than for Mg+2
• not functional with Ca+2 or Cu+2
• RAN inhibits its autophosphorylation & its ability to phosphorylate histone H3
• autophosphorylated at various Ser & Thr
• autophosphorylation does not impair its ability to phosphorylate p53/TP53

Structure

• belongs to the protein kinase superfamily, CK1 Ser/Thr protein kinase family, VRK subfamily
• contains 1 protein kinase domain

Compartment

• cytoplasm, nucleus, cytoskeleton, spindle (putative)
• dispersed throughout the cell & not located on mitotic spindle or chromatids during mitosis

Expression

• widely expressed
• highly expressed in fetal liver, testis & thymus

Pathology

• defects in VRK1 are the cause of pontocerebellar hypoplasia type 1

More general terms

• serine/threonine protein kinase VRK (Vaccinia-related kinase)

Additional terms

• vaccinia virus

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=7443
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:7443
• OMIM: https://mirror.omim.org/entry/602168
• OMIM: https://mirror.omim.org/entry/607596
• UniProt: http://www.uniprot.org/uniprot/Q99986.html