RESUMO
We report the cloning, genomic organization and sequence of the mouse alpha-CALC and beta-CALC genes. The two genes share extensive sequence homology. The transcription units of both genes contain 6 exons. Transcripts of the alpha-CALC gene were found to alternatively include exon 4 or exons 5 and 6. For the beta-CALC gene exon 4 was not detected in transcripts derived from this gene. The predicted mouse alpha-CGRP was found to be identical to rat alpha-CGRP, however, beta-CGRP predicted amino acid sequences revealed three amino acid differences suggesting these residues are not critical to CGRP function.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/genética , Calcitonina/genética , Animais , Sequência de Bases , Camundongos , Dados de Sequência Molecular , Homologia de SequênciaRESUMO
Sulfonylurea receptors (SURx) are required subunits of the ATP-sensitive potassium channel. SURx alone is electrophysiologically inert. However, when SURx is combined with an inward rectifier Kir6.2 subunit, ATP-sensitive potassium channel activity is generated. We report the identification, characterization, and localization of Dsur, a novel Drosophila gene that is highly related to the vertebrate SUR family. The Dsur coding sequence contains structural features characteristic of the ABC transporter family and, in addition, harbors 1.7 kilobases of a distinctive sequence that does not share homology with any known gene. When Dsur alone is expressed in Xenopus oocytes glibenclamide-sensitive potassium channel activity occurs. During Drosophila embryogenesis, the Dsur gene is specifically expressed in the developing tracheal system and dorsal vessel. Studies of the Drosophila genome support that only a single Dsur gene is present. Our data reveal conservation of glibenclamide-sensitive potassium channels in Drosophila and suggest that Dsur may play an important role during Drosophila embryogenesis. The lack of gene duplication in the Drosophila system provides a unique opportunity for functional studies of SUR using a genetic approach.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Drosophila , Drosophila/genética , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/genética , Receptores de Droga/genética , Transportadores de Cassetes de Ligação de ATP/química , Sequência de Aminoácidos , Animais , Clonagem Molecular , Drosophila/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Glibureto/farmacologia , Humanos , Hibridização In Situ , Dados de Sequência Molecular , Oócitos , Técnicas de Patch-Clamp , Filogenia , Canais de Potássio/química , RNA Mensageiro/metabolismo , Receptores de Droga/química , Receptores de Sulfonilureias , Xenopus laevisRESUMO
Using a bovine rod photoreceptor cell-specific ATP-binding cassette (ABC) transporter cDNA we have cloned the full-length transcript of the homologous human gene and demonstrate that it is identical to the photoreceptor cell-specific ABC transporter (ABCR) recently shown to be mutated in Stargardt's disease. By fluorescence in situ hybridization we have mapped the ABCR gene to chromosomal band 1p21-p22.1. Mutational analysis of part of the gene in 15 Stargardt's disease patients has identified four disease-causing mutations, of which two represent potential null alleles. This brings the total number of independently identified mutations to 23, providing further evidence that the human ABCR gene is associated with Stargardt's disease.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 1/genética , Degeneração Macular/genética , Mutação , Segmento Externo da Célula Bastonete/metabolismo , Transportadores de Cassetes de Ligação de ATP/biossíntese , Clonagem Molecular , Análise Mutacional de DNA , Expressão Gênica , Humanos , Dados de Sequência Molecular , Linhagem , Retina/metabolismoAssuntos
Apolipoproteína A-I/genética , Expressão Gênica , Fígado/metabolismo , Células 3T3 , Animais , Linhagem Celular , Técnicas de Transferência de Genes , Genes Bacterianos , Vetores Genéticos , Células HeLa , Humanos , Camundongos , Plasmídeos , Regiões Promotoras Genéticas , Ratos , Ratos Wistar , Retroviridae/genéticaRESUMO
Absorptive hypercalciuria (a stone-forming condition) is characterized by gut hyperabsorption of calcium, hypercalciuria, and reduced bone density. Inasmuch as these features implicate enhanced calcitriol action in gut and bone, we analyzed the vitamin D receptor (VDR) gene to ascertain whether an abnormality of this gene marks patients with intestinal hyperabsorption of calcium. We have compared the frequency of a restriction fragment length polymorphism (Bsm I) associated with different alleles of the VDR gene in a group of 33 well characterized absorptive hypercalciuric patients and a group of 36 normal race- and age-matched control subjects. There was no difference between the distribution of the VDR alleles in the patient population when compared with the normal population. The coding region of VDR messenger RNA was also normal, as determined by both DNA sequence analysis and chemical mismatch cleavage analysis of copy DNA from 11 index absorptive hypercalciuric patients. On the basis of these results, we propose that the enhanced intestinal calcium absorption invariably seen in absorptive hypercalciuria and attendant symptoms of this disorder are not attributable to mutations of the VDR and are not linked to a common VDR genotype.
Assuntos
Cálcio/metabolismo , Cálcio/urina , Síndromes de Malabsorção/genética , Polimorfismo de Fragmento de Restrição , Receptores de Calcitriol/biossíntese , Receptores de Calcitriol/genética , Alelos , Sequência de Bases , Biópsia , Densidade Óssea , Calcitriol/sangue , Cálcio/sangue , Células Cultivadas , Creatinina/urina , Desoxirribonuclease BamHI , Desoxirribonucleases de Sítio Específico do Tipo II , Éxons , Feminino , Genótipo , Humanos , Absorção Intestinal , Leucócitos/metabolismo , Síndromes de Malabsorção/metabolismo , Masculino , Dados de Sequência Molecular , Hormônio Paratireóideo/sangue , Fosfatos/sangue , Reação em Cadeia da Polimerase , Pré-Menopausa , RNA Mensageiro/metabolismo , Valores de Referência , Pele/metabolismo , Pele/patologiaRESUMO
Elevations of plasma total or LDL cholesterol are major risk factors for cardiovascular disease. Efforts directed at preventing and treating cardiovascular disease have often focused on reducing the levels of these substances in the blood. The Watanabe Heritable Hyperlipidemic Rabbit, which has exceedingly high plasma cholesterol levels resulting from an LDL receptor deficiency, provides an excellent animal model for testing new treatments. A recombinant adenoviral vector containing the rabbit LDL receptor cDNA was administered to Watanabe rabbits. Plasma total cholesterol levels in the treated animals were reduced from 825.5 +/- 69.8 (mean +/- SD) to 247.3 +/- 61.5 mg/dl 6 d after infusion. These animals also demonstrated a 300-400% increase in plasma levels of HDL cholesterol and apo AI 10 d after treatment. As a result, the LDL:HDL ratio exhibited a dramatic decrease. Because only the rabbit LDL receptor gene was used for treatment, the results strongly suggest that the elevations of plasma HDL cholesterol and apo AI were secondary to a reduction in plasma total cholesterol in the treated animals. These results suggest an inverse relationship between plasma LDL and HDL cholesterol levels and imply that reduction of LDL cholesterol levels may have a beneficial effect on plasma HDL cholesterol.