Transient expression and mutational analysis of the rotavirus intracellular receptor: the C-terminal methionine residue is essential for ligand binding.
AUTOR(ES)
Taylor, J A
RESUMO
Maturation of rotavirus involves an intracellular membrane budding event in which the single-shelled icosahedral particle interacts with a virus-encoded receptor glycoprotein, NS28, that is located in the rough endoplasmic reticulum membrane. The receptor is a tetramer and is oriented with the C-terminal 131 amino acids on the cytoplasmic side of the membrane (A.R. Bellamy and G.W. Both, Adv. Virus Res. 38:1-48, 1990). We have used the T7-vaccinia virus transient expression system to deliver mutant variants of the NS28 gene to CV1 cells in order to assess the effects of site-specific modifications on receptor function. Three types of mutant proteins have been constructed by altering the extreme C-terminal methionine, cysteine residues within the third hydrophobic domain, and internal residues located within the cytoplasmic portion of the receptor, respectively. Deletion or conservative substitution of the C-terminal methionine completely abolishes receptor activity. Substitution of cysteine residues has no effect on receptor activity or on the ability of the receptor to adopt its native oligomeric state. Internal deletions result only in a reduction in the level of binding. An N-terminally truncated form of the receptor, containing only the cytoplasmic domain, retains full receptor activity and can form membrane-associated tetramers.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=241138Documentos Relacionados
- Mutations in the C-terminal fragment of DnaK affecting peptide binding.
- Activity of the Mitogenic Pasteurella multocida Toxin Requires an Essential C-Terminal Residue
- Mutational Analysis Defines a C-Terminal Tail Domain of Rap1 Essential for Telomeric Silencing in Saccharomyces Cerevisiae
- The Kex2p Proregion Is Essential for the Biosynthesis of an Active Enzyme and Requires a C-terminal Basic Residue for Its Function
- The C-terminal domain of the Bloom syndrome DNA helicase is essential for genomic stability