Common variations in noncoding regions of the human natriuretic peptide receptor A gene have quantitative effects

Abstract

Genetic susceptibility to common conditions, such as essential hypertension and cardiac hypertrophy, is probably determined by various combinations of small quantitative changes in the expression of many genes. NPR1, coding for natriuretic peptide receptor A (NPRA), is a potential candidate, because NPRA mediates natriuretic, diuretic, and vasorelaxing actions of the nariuretic peptides, and because genetically determined quantitative changes in the expression of this gene affect blood pressure and heart weight in a dose-dependent manner in mice. To determine whether there are common quantitative variants in human NPR1, we have sequenced the entire human NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript NPR1 gene and identified 10 polymorphic sites in its non-coding sequence by using DNA from 34 unrelated human individuals. Five of the sites are single nucleotide polymorphisms; the remaining five are length polymorphisms, including a highly variable complex dinucleotide repeat in intron 19. There are three common haplotypes 5' to this dinucleotide repeat and three 3' to it, but the 5' haplotypes and 3' haplotypes appear to be randomly associated. Transient expression analysis in cultured cells of reporter plasmids with the proximal promoter sequences of NPR1 and its 3' untranslated regions showed that these polymorphisms have functional effects. We conclude that common NPR1 alleles can alter expression of the gene as much as two-fold and could therefore significantly affect genetic risks for essential hypertension and cardiac hypertrophy in humans.

Association of CT Dinucleotide Repeat Polymorphism in the 5'-Flanking Region of the Guanylyl Cyclase (GC)-A Gene with Essential Hypertension in the Japanese

“…Our observation that the CT6-containing GC-A promoter drives less transcription in human AoSMCs than the CT10-containing promoter is in contrast to the findings of Knowles et al, who reported that, in mouse AoSMCs, the transcriptional activity of the human CT6-containing promoter was significantly greater than the activities of the CT10-and CT11-containing promoters (15). One possible explanation for this discrepancy is that they used a promoter fragment extending from −770 bp to the ATG start codon to assess transcriptional activity, whereas we used a fragment extending from position −1425 to −41 bp.…”

“…Earlier reports also showed that the (CT)n= 6 allele is linked to an A at position −77 in the GC-A promoter region and that the (CT)n= 10 and 11 alleles are linked to a G at that position (15). We confirmed this linkage and found that the (CT)n= 9 and 12 alleles also are linked to a G at position −77.…”

“…In addition, plasma ANP and BNP levels did not differ between subjects with and those without the (CT)n= 6 allele. It was suggested in an earlier report that there may be a linkage between the (CT)n and G/A polymorphisms in some healthy subjects (15). Bearing that in mind, we next examined the linkage between the (CT)n and G/A polymorphisms in our study subjects.…”

“…Nakayama et al identified an insertion/deletion polymorphism (8 bp deletion) at position −60 and a (CT)n dinucleotide repeat polymorphism at position −293 of the gene in a Japanese population (13,14). In addition, Knowles et al also identified the (CT)n dinucleotide repeat site as well as nine other polymorphic sites in the noncoding region of the gene (15). These polymorphisms in the 5′-flanking region and other noncoding regions could affect the transcriptional activity of the GC-A gene and are thus potentially involved in the pathogenesis of essential hypertension.…”

Structure, Regulation, and Function of Mammalian Membrane Guanylyl Cyclase Receptors, With a Focus on Guanylyl Cyclase-A

“…108,109 For GC-A, the association between a functional deletion mutation in the promoter region of the human GC-A gene, decreased receptor expression, and EH as well as ventricular hypertrophy has been shown in the Japanese population 110 but not in European patients with EH. 111 Knowles et al 112 recently identified 10 additional polymorphic sites in the noncoding sequence of GC-A and, by transient expression analysis, demonstrated that they can alter GC-A expression as much as 2-fold. Last, a promoter variant of the NPR-C gene has been shown to be associated with lower ANP levels and higher blood pressure in obese hypertensives.…”