Structure and polymorphisms of the human natriuretic peptide receptor C gene.

Natriuretic peptides (NPs) regulate cardiovascular homeostasis, including natriuresis, diuresis, vasodilation, regulation of endocrine secretion, and inhibition of cellular growth. Atrial natriuretic peptide receptor C (NPRC) has a short cytoplasmic domain that lacks guanylyl cyclase activity. We used information available for the cDNA of human NPRC to amplify products covering all genomic regions of the gene by long polymerase chain reaction (PCR) and thermal asymmetric interlaced (TAIL)-PCR. PCR products were sequenced directly after extraction and purification. The human NPRC gene spans > 65 kb and contains eight exons and seven introns. All of the exon-intron junction sequences contain the GT/AG consensus junction sequence. We then used the PCR-single-strand conformation polymorphism (PCR-SSCP) to identify polymorphisms of the human NPRC gene. All eight exons and neighboring introns were analyzed by PCR-SSCP for 96 subjects, and migration variants were observed for intron 1, exon 2, and exon 5. Direct sequencing of these variants revealed the following sequence differences: a C to T transition in intron 1, an A to C transition in exon 2, and a C to T transition in exon 5. PCR-restriction fragment length polymorphism analysis (PCR-RFLP) was used to evaluate all three variations. We have determined the structural organization and identified polymorphic sites in the human NPRC gene. The results of this study will facilitate further genetic analyses of the human NPRC gene function.