Isolation and Characterization of Plant N-Acetyl Glucosaminyltransferase I (GntI) cDNA Sequences. Functional Analyses in the Arabidopsis cgl Mutant and in Antisense Plants1
AUTOR(ES)
Wenderoth, Irina
FONTE
American Society of Plant Physiologists
RESUMO
We report on the isolation and characterization of full-length cDNA sequences coding for N-acetylglucosaminyltransferase I (GnTI) from potato (Solanum tuberosum L.), tobacco (Nicotiana tabacum L.), and Arabidopsis. The deduced polypeptide sequences show highest homology among the solanaceous species (93% identity between potato and tobacco compared with about 75% with Arabidopsis) but share only weak homology with human GnTI (35% identity). In contrast to the corresponding enzymes from animals, all plant GnTI sequences identified are characterized by a much shorter hydrophobic membrane anchor and contain one putative N-glycosylation site that is conserved in potato and tobacco, but differs in Arabidopsis. Southern-blot analyses revealed that GntI behaves as a single-copy gene. Northern-blot analyses showed that GntI-mRNA expression is largely constitutive. Arabidopsis cgl mutants deficient in GnTI activity also possess GntI mRNA, indicating that they result from point mutations. GntI-expression constructs were tested for the ability to relieve the GnTI block in protoplasts of the Arabidopsis cgl mutant and used to obtain transgenic potato and tobacco plants that display a substantial reduction of complex glycan patterns. The latter observation indicates that production of heterologous glycoproteins with little or no antigenic glycans can be achieved in whole plants, and not in just Arabidopsis, using antisense technology.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=59073Documentos Relacionados
- Isolation of a mutant Arabidopsis plant that lacks N-acetyl glucosaminyl transferase I and is unable to synthesize Golgi-modified complex N-linked glycans.
- N-acetyl endorphin in rat spermatogonia and primary spermatocytes.
- Effect of N-acetyl cysteine on thiol levels.
- N-acetyl muramyl dipeptide stimulation of bone resorption in tissue culture.
- Peptidoglycan of Rhodopseudomonas viridis: partial lack of N-acetyl substitution of glucosamine.