Complex haplotypes derived from noncoding polymorphisms of the intronless alpha2A-adrenergic gene diversify receptor expression

@article{citeulike:695525, abstract = {{alpha} 2A-adrenergic receptors ({alpha}2AAR) regulate multiple central nervous system, cardiovascular, and metabolic processes including neurotransmitter release, platelet aggregation, blood pressure, insulin secretion, and lipolysis. Complex diseases associated with {alpha}2AAR dysfunction display familial clustering, phenotypic heterogeneity, and interindividual variability in response to therapy targeted to {alpha}2AARs, suggesting common, functional polymorphisms. In a multiethnic discovery cohort we identified 16 single-nucleotide polymorphisms (SNPs) in the {alpha}2AAR gene organized into 17 haplotypes of two major phylogenetic clades. In contrast to other adrenergic genes, variability of the {alpha}2AAR was primarily due to SNPs in the promoter, 5' UTR and 3' UTR, as opposed to the coding block. Marked ethnic variability in the frequency of SNPs and haplotypes was observed: one haplotype represented 70\% of Caucasians, whereas Africans and Asians had a wide distribution of less common haplotypes, with the highest haplotype frequencies being 16\% and 35\%, respectively. Despite the compact nature of this intronless gene, local linkage disequilibrium between a number of SNPs was low and ethnic-dependent. Whole-gene transfections into BE(2)-C human neuronal cells using vectors containing the entire {approx}5.3-kb gene without exogenous promoters were used to ascertain the effects of haplotypes on {alpha}2AAR expression. Substantial differences (P < 0.001) in transcript and cell-surface protein expression, by as much as {approx}5-fold, was observed between haplotypes, including those with common frequencies. Thus, signaling by this virtually ubiquitous receptor is under major genetic influence, which may be the basis for highly divergent phenotypes in complex diseases such as systemic and pulmonary hypertension, heart failure, diabetes, and obesity. 10.1073/pnas.0601345103}, author = {Small, Kersten M. and Brown, Kari M. and Seman, Carrie A. and Theiss, Cheryl T. and Liggett, Stephen B. }, citeulike-article-id = {695525}, journal = {PNAS}, keywords = {2, alpha, genetics}, month = {April}, number = {14}, pages = {5472--5477}, posted-at = {2006-06-14 10:09:02}, priority = {2}, title = {Complex haplotypes derived from noncoding polymorphisms of the intronless {alpha}2A-adrenergic gene diversify receptor expression}, url = {http://www.pnas.org/cgi/content/abstract/103/14/5472}, volume = {103}, year = {2006} }

TY - JOUR ID - citeulike:695525 L3 - citeulike-article-id:695525 TI - Complex haplotypes derived from noncoding polymorphisms of the intronless {alpha}2A-adrenergic gene diversify receptor expression JF - PNAS VL - 103 IS - 14 SP - 5472 EP - 5477 N2 - {alpha} 2A-adrenergic receptors ({alpha}2AAR) regulate multiple central nervous system, cardiovascular, and metabolic processes including neurotransmitter release, platelet aggregation, blood pressure, insulin secretion, and lipolysis. Complex diseases associated with {alpha}2AAR dysfunction display familial clustering, phenotypic heterogeneity, and interindividual variability in response to therapy targeted to {alpha}2AARs, suggesting common, functional polymorphisms. In a multiethnic discovery cohort we identified 16 single-nucleotide polymorphisms (SNPs) in the {alpha}2AAR gene organized into 17 haplotypes of two major phylogenetic clades. In contrast to other adrenergic genes, variability of the {alpha}2AAR was primarily due to SNPs in the promoter, 5' UTR and 3' UTR, as opposed to the coding block. Marked ethnic variability in the frequency of SNPs and haplotypes was observed: one haplotype represented 70% of Caucasians, whereas Africans and Asians had a wide distribution of less common haplotypes, with the highest haplotype frequencies being 16% and 35%, respectively. Despite the compact nature of this intronless gene, local linkage disequilibrium between a number of SNPs was low and ethnic-dependent. Whole-gene transfections into BE(2)-C human neuronal cells using vectors containing the entire {approx}5.3-kb gene without exogenous promoters were used to ascertain the effects of haplotypes on {alpha}2AAR expression. Substantial differences (P < 0.001) in transcript and cell-surface protein expression, by as much as {approx}5-fold, was observed between haplotypes, including those with common frequencies. Thus, signaling by this virtually ubiquitous receptor is under major genetic influence, which may be the basis for highly divergent phenotypes in complex diseases such as systemic and pulmonary hypertension, heart failure, diabetes, and obesity. 10.1073/pnas.0601345103 KW - 2 KW - alpha KW - genetics AU - Small, Kersten AU - Brown, Kari AU - Seman, Carrie AU - Theiss, Cheryl AU - Liggett, Stephen PY - 2006/04/04/ UR - http://www.pnas.org/cgi/content/abstract/103/14/5472 ER -