Alternative titles; symbols
HGNC Approved Gene Symbol: STK19
Cytogenetic location: 6p21.33 Genomic coordinates (GRCh38) : 6:31,971,175-31,981,446 (from NCBI)
The STK19 gene encodes a nuclear serine/threonine protein kinase (Gomez-Escobar et al., 1998).
By screening cDNA libraries using a DNA fragment upstream of the C4A gene (120810), which is localized to the class III region of the MHC, followed by RT-PCR, Shen et al. (1994) isolated a cDNA encoding STK19, which they named RP in honor of the Nobel laureate immunochemist Sir Rodney R. Porter. The predicted 364-amino acid STK19 protein has an extremely hydrophilic N-terminal half and a C-terminal half with alternating hydrophilic and hydrophobic regions. STK19 contains a positively charged putative nuclear localization signal, multiple potential phosphorylation sites, 2 amidation sites, 9 potential N-myristoylation sites, and no N-glycosylation sites. Northern blot analysis of various cell lines revealed ubiquitous expression of a 1.6- to 1.8-kb STK19 transcript.
By screening BamHI-digested DNA on a zoo blot using a CpG island-rich probe derived from an MHC cosmid clone, followed by screening a phorbol ester-stimulated monocytic cell line using a genomic DNA fragment upstream of the C4A gene, Sargent et al. (1994) isolated a cDNA encoding a 258-amino acid STK19 protein. The authors referred to the STK19 gene as G11 and the 258-amino acid protein as G11-Y. They also identified an inphase STK19 splice variant of 254 amino acids. Homology searches found limited sequence similarity with a number of proteins; the most significant similarity was with the tyrosine kinase transforming protein of fujinami sarcoma virus. Northern blot analysis detected a 1.4-kb STK19 transcript in multiple cell lines, suggesting ubiquitous expression.
Gomez-Escobar et al. (1998) showed that the 368-amino acid STK19 protein (Shen et al., 1994), which they termed G11-Z, and the 258-amino acid STK19 protein (G11-Y; Sargent et al., 1994), which lacks the N-terminal 110 amino acids present in G11-Z, are both intracellular proteins. Immunoprecipitation and Western blot analyses determined that the STK19 gene is expressed as 41.5-kD (G11-Z) and 30-kD (G11-Y) proteins. Functional analysis demonstrated that STK19 has a manganese-dependent protein kinase activity that phosphorylates alpha-casein (CSN1; 115450) at ser/thr residues and histone (see 142711) at ser residues. Immunofluorescence microscopy showed that STK19 is localized primarily in the nucleus.
Shen et al. (1994) determined that the STK19 gene contains 9 exons. The 5-prime region of the STK19 gene is rich in CpG sequences, which is typical of a housekeeping gene, and there are 8 Alu elements in intron 4.
By genomic sequence analysis using the G11-Y cDNA, Sargent et al. (1994) determined that the STK19 gene contains 7 exons and spans 9.1 kb.
Shen et al. (1994) identified the STK19 gene on chromosome 6p21.3, 611 bp upstream of the C4A gene.
Gomez-Escobar, N., Chou, C.-F., Lin, W.-W., Hsieh, S.-L., Campbell, R. D. The G11 gene located in the major histocompatibility complex encodes a novel nuclear serine/threonine protein kinase. J. Biol. Chem. 273: 30954-30960, 1998. [PubMed: 9812991] [Full Text: https://doi.org/10.1074/jbc.273.47.30954]
Sargent, C. A., Anderson, M. J., Hsieh, S.-L., Kendall, E., Gomez-Escobar, N., Campbell, R. D. Characterisation of the novel gene G11 lying adjacent to the complement C4A gene in the human major histocompatibility complex. Hum. Molec. Genet. 3: 481-488, 1994. [PubMed: 8012361] [Full Text: https://doi.org/10.1093/hmg/3.3.481]
Shen, L., Wu, L., Sanlioglu, S., Chen, R., Mendoza, A. R., Dangel, A. W., Carroll, M. C., Zipf, W. B., Yu, C. Y. Structure and genetics of the partially duplicated gene RP located immediately upstream of the complement C4A and the C4B genes in the HLA class III region: molecular cloning, exon-intron structure, composite retroposon, and breakpoint gene duplication. J. Biol. Chem. 269: 8466-8476, 1994. [PubMed: 8132574]