|
|
| Id: |
lil-435425
|
| Autor: |
Handford, M; Rodriguez-Furlán, C; Orellana, A. |
| Título: |
Nucleotide-sugar transporters: structure, function and roles in vivo |
| Fonte: |
Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;39(9):1149-1158, Sept. 2006. ilus.
|
| Idioma: |
en.
|
| Conferência: |
Apresentado em: Annual Meeting of the Federação de Sociedades de Biologia Experimental, 18, Curitiba, Aug. 27-30, 2003.
|
| Projeto: |
The Leverhulme Trust; . El Fondo Nacional de Desarrollo Científico y Tecnológico; . Iniciativa Científica Milenio.
|
| Resumo: |
The glycosylation of glycoconjugates and the biosynthesis of polysaccharides depend on nucleotide-sugars which are the substrates for glycosyltransferases. A large proportion of these enzymes are located within the lumen of the Golgi apparatus as well as the endoplasmic reticulum, while many of the nucleotide-sugars are synthesized in the cytosol. Thus, nucleotide-sugars are translocated from the cytosol to the lumen of the Golgi apparatus and endoplasmic reticulum by multiple spanning domain proteins known as nucleotide-sugar transporters (NSTs). These proteins were first identified biochemically and some of them were cloned by complementation of mutants. Genome and expressed sequence tag sequencing allowed the identification of a number of sequences that may encode for NSTs in different organisms. The functional characterization of some of these genes has shown that some of them can be highly specific in their substrate specificity while others can utilize up to three different nucleotide-sugars containing the same nucleotide. Mutations in genes encoding for NSTs can lead to changes in development in Drosophila melanogaster or Caenorhabditis elegans, as well as alterations in the infectivity of Leishmania donovani. In humans, the mutation of a GDP-fucose transporter is responsible for an impaired immune response as well as retarded growth. These results suggest that, even though there appear to be a fair number of genes encoding for NSTs, they are not functionally redundant and seem to play specific roles in glycosylation.
|
| Descritores: |
Retículo Endoplasmático/metabolismo
Complexo de Golgi/metabolismo
Açúcares de Nucleosídeo Difosfato/metabolismo
Proteínas de Transporte de Nucleotídeos/metabolismo
|
| |
-Sequência de Aminoácidos
Transporte Biológico
Glicosilação
Dados de Sequência Molecular
Açúcares de Nucleosídeo Difosfato/síntese química
Açúcares de Nucleosídeo Difosfato/genética
Proteínas de Transporte de Nucleotídeos/química
Proteínas de Transporte de Nucleotídeos/genética
Relação Estrutura-Atividade
Especificidade por Substrato
|
| Limites: |
Humanos
Animais
|
| Responsável: |
BR1.1 - BIREME
|
|
