Alternative titles; symbolsPROTEIN KINASE PKX1; PKX1HGNC Approved Gene Symbol: PRKXCytogenetic location: Xp22.33 Genomic coordinates (GRCh38): X:3,604,339-3,...
Alternative titles; symbols
HGNC Approved Gene Symbol: PRKX
Cytogenetic location: Xp22.33 Genomic coordinates (GRCh38): X:3,604,339-3,713,648 (from NCBI)
▼ Cloning and Expression
In a search for genes within the critical region for chondrodysplasia punctata, Klink et al. (1995) isolated a novel gene, which they designated PKX1, on Xp22.3. The deduced 358-amino acid protein showed high homology to cAMP-dependent protein kinases and shared 57% identity over 357 amino acids to the DC kinase of Drosophila. Northern blot analysis revealed widespread expression of PKX1, with highest expression in fetal and adult brain, kidney, and lung.
Klink et al. (1995) found that PKX1 is part of a family of at least 4 genes or pseudogenes, of which 3 map to the human sex chromosomes. In contrast to all other genes from the X-specific region of Xp22.3, PKX1 has a homolog on Yp (PRKY; 400008) rather than Yq. This suggests that the single pericentric inversion event hypothesized to have occurred during primate evolution is not sufficient to explain the present X/Y homology pattern of Xp22.3. Klink et al. (1995) found that a high proportion of the chromosomal rearrangements in Xp22.3 or Yp occurred within the PKX1 locus. This suggests that the PKX1 gene, besides harboring a previously described hotspot for illegitimate Xp/Yp recombination, contains additional sequences which predispose the X chromosome to breakage events.
Schiebel et al. (1997) used FISH analysis to map the Y homolog of PRKX (PRKY) to Yp11.2 in close proximity to AMELY (410000); the autosomal copy, a pseudogene (PRKXP1), to 15q26; and a further X-linked pseudogene (PRKXP2) to Xq12-q13.
▼ Gene Function
Renal expression of the PRKX gene is developmentally regulated and restricted to the ureteric bud epithelium of the fetal metanephric kidney. Li et al. (2002) found aberrant adult kidney expression of PRKX in autosomal dominant polycystic kidney disease (PKD1; 601313). PRKX kinase expression markedly activated migration of cultured renal epithelial cells in the presence of cAMP; this effect was blocked by cell treatment with the PKA inhibitor H89 and was not observed in PKA-transfected cells. These and other results suggested that the PRKX kinase may regulate epithelial morphogenesis during mammalian kidney development.