RESUMO
Ral GDP dissociation stimulator (RalGDS) and its family members RGL, RLF and RGL2 are involved in Ras and Ral signaling pathways as downstream effector proteins. Here we report the precise localization and cloning of two forms of human RGL gene differing at the amino terminus. Transcript A, cloned from liver cDNA libraries has the same amino terminus as the mouse RGL, whereas transcript B cloned from brain has a substitution of 45 amino acids for the first nine amino acids. At the genomic level, exon 1 of transcript A is replaced by two alternative exons (1B1 and 1B2) in transcript B. Both forms share exons 2 through 18. The human RGL protein shares 94% amino acid identity with the mouse protein. Northern blot analysis shows that human RGL is expressed in a wide variety of tissues with strong expression being seen in the heart, brain, kidney, spleen and testis.
Assuntos
Fatores de Troca do Nucleotídeo Guanina/genética , Sequência de Aminoácidos , Northern Blotting , Encéfalo/metabolismo , Clonagem Molecular , DNA Complementar/genética , Expressão Gênica , Humanos , Fígado/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Proteínas ras/metabolismoRESUMO
A novel human transcript CG-2 (C9ORF5), was isolated from the familial dysautonomia candidate region on 9q31 using a combination of cDNA selection and exon trapping. CG-2 was detected as a relatively abundant 8kb transcript in all adult and fetal tissues with the exception of adult thymus. Genomic analysis of CG-2 identified 18 exons that span more than 110kb. The gene encodes a 911-amino-acid protein with a predicted molecular weight of 101kDa and a hypothetical pI of 9.03. Sequence analysis of CG-2 indicates that it is likely to encode a transmembrane protein. Here, we assess CG-2 as a candidate for familial dysautonomia.
Assuntos
Genes de Helmintos/genética , Genes/genética , Proteínas de Membrana/genética , Adulto , Sequência de Aminoácidos , Animais , Encéfalo/embriologia , Encéfalo/metabolismo , Caenorhabditis elegans/genética , Linhagem Celular , Mapeamento Cromossômico , Cromossomos Humanos Par 9/genética , Clonagem Molecular , Cricetinae , DNA/química , DNA/genética , Análise Mutacional de DNA , DNA Complementar/química , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Bases de Dados Factuais , Disautonomia Familiar/genética , Etiquetas de Sequências Expressas , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Células Híbridas , Camundongos , Dados de Sequência Molecular , Ratos , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
The crystal structure of a putative metal-chelate-type adenosine triphosphate (ATP)-binding cassette (ABC) transporter encoded by genes HI1470 and HI1471 of Haemophilus influenzae has been solved at 2.4 angstrom resolution. The permeation pathway exhibits an inward-facing conformation, in contrast to the outward-facing state previously observed for the homologous vitamin B12 importer BtuCD. Although the structures of both HI1470/1 and BtuCD have been solved in nucleotide-free states, the pairs of ABC subunits in these two structures differ by a translational shift in the plane of the membrane that coincides with a repositioning of the membrane-spanning subunits. The differences observed between these ABC transporters involve relatively modest rearrangements and may serve as structural models for inward- and outward-facing conformations relevant to the alternating access mechanism of substrate translocation.
Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Proteínas de Bactérias/química , Haemophilus influenzae/química , Domínio Catalítico , Cristalografia por Raios X , Dimerização , Metais/metabolismo , Modelos Moleculares , Conformação Proteica , Dobramento de Proteína , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Subunidades Proteicas/químicaRESUMO
Two novel human actin-like genes, ACTL7A and ACTL7B, were identified by cDNA selection and direct genomic sequencing from the familial dysautonomia candidate region on 9q31. ACTL7A encodes a 435-amino-acid protein (predicted molecular mass 48.6 kDa) and ACTL7B encodes a 415-amino-acid protein (predicted molecular mass 45. 2 kDa) that show greater than 65% amino acid identity to each other. Genomic analysis revealed ACTL7A and ACTL7B to be intronless genes contained on a common 8-kb HindIII fragment in a "head-to-head" orientation. The murine homologues were cloned and mapped by linkage analysis to mouse chromosome 4 in a region of gene order conserved with human chromosome 9q31. No recombinants were observed between the two genes, indicating a close physical proximity in mouse. ACTL7A is expressed in a wide variety of adult tissues, while the ACTL7B message was detected only in the testis and, to a lesser extent, in the prostate. No coding sequence mutations, genomic rearrangements, or differences in expression were detected for either gene in familial dysautonomia patients.