13 exons in 84.22 kilobases. Transcription initiated from cetromere to telomere direction.

Initiation codon located in exon 2. Normal message is 1702 nucleotides. Some alternatively spliced RNA messages have been detected; but they are likely to represent splicing intermediates since there is no protein has been detected expressed from these alternative messages in humans.

None.
There are two closely related genes VRK2 and VRK3.
SNP: 289 single nucleotide polymorphisms identified in human VRK1.
ALLELE VARIANTS: CA Polymorphisms. Near the PAPOLA (Polyadenyl polymerase) with respect to VRK1 there is a polymorphic dinucleotide (CA) sequence that has high heterozygosity (0.81). Might be a useful marker in the genetic study of disorders localized at the 14q32 region, such as autosomal recessive congenital microphthalmia (CMIC).

Enzyme Number (IUBMB): "EC 2.7.11.1".

Protein of 396 aminoacids. 46 kDa. Serine-threonine kinase domain (residues 26-300). Nuclear localization signal (in C-terminal region) Protein autophosphorylated in several residues.

VRK1 is widely expressed in proliferating cells, normal and tumoral. It is not present in quiescent or differentiated cells that do not divide in human biopsies.

Subcellular localisation varies depending on cell type and growth conditions. Most commonly VRK1 is expressed and detected in the nucleus, excluding the nucleolus. However, in some cells it is in the cytosol, particularly associated with endoplasmic reticulum and Golgi.
Occasionally it is observed in the nucleolus, but outside the nucleus .The regulation of the subcellular localization is unknown.

Serine-threonine kinase activity.
Phosphorylates p53 in Threonine-18 preventing its interaction with Hdm2 and activates p53-dependent transcription. Phosphorylates c-Jun and ATF2 transcription factors. VRK1 also phosphorylates BAF1 required for nuclear envelope assembly.
In human cell lines siRNA specific for VRK1 results in defective cell proliferation. The level of VRK1 protein is regulated proteolytically by a p53-dependent-transcription mechanism. This mechanism results in the induction of a targeting of VRK1 to enter the endosomal-lysosomal pathway.

The kinase domain is highly homologous to that in other ser-thr kinases. The C-terminal region has no homology to any known protein or domain. This C-terminal region of VRK1 is different form that in human VRK2, or in the VRK-1 homolog of distant species such as Drosophila, C. elegans or Dario Rerio. This C-terminal divergence suggest the possibility of different protein interactions and thus of differential regulation.

All mutations reported in study by Greenman el al. 2007.

Normal:
Mutation in nucleotide 45 in the cDNA coding region ; A to G that is silent (A15A).
Mutation in nucleotide 705 in the cDNA coding region ; C to T that is silent (G235G).

Colorectal carcinoma:
Heterozygous mutation in nucleotide 42 in the cDNA coding region; T to C (silent S14S).