Redundancy of signal and anchor functions in the NH2-terminal uncharged region of influenza virus neuraminidase, a class II membrane glycoprotein.
AUTOR(ES)
Brown, D J
RESUMO
Class II membrane glycoproteins share a common topology of the NH2 terminus inside and the COOH terminus outside the cell. Their transport to the cell surface is initiated by the function of a single hydrophobic domain near the NH2 terminus. This functional domain serves both as an uncleaved signal sequence and as a transmembrane anchor. We examined the signal and anchor functions of influenza virus neuraminidase, a prototype class II membrane glycoprotein, by deletion analysis of its long, uncharged amino-terminal region. The results presented here show that the entire stretch of 29 uncharged amino acids (7 to 35) is not required for either a signal sequence or an anchor sequence function. On the basis of translocation and membrane stability data for different mutants, we suggest that the first 20 amino acid residues (7 to 27) are likely to provide the hydrophobic core for these functions and that within this putative subdomain some sequences are more efficient than the other sequences in providing a translocation function. Finally, it appears that neuraminidase and its mutant proteins are translocated with the proper orientation, regardless of the characteristics of the flanking sequences.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=253528Documentos Relacionados
- NH2-terminal hydrophobic region of influenza virus neuraminidase provides the signal function in translocation.
- Determination of the orientation of an integral membrane protein and sites of glycosylation by oligonucleotide-directed mutagenesis: influenza B virus NB glycoprotein lacks a cleavable signal sequence and has an extracellular NH2-terminal region.
- Surface expression of influenza virus neuraminidase, an amino-terminally anchored viral membrane glycoprotein, in polarized epithelial cells.
- Analysis of the Transmembrane Domain of Influenza Virus Neuraminidase, a Type II Transmembrane Glycoprotein, for Apical Sorting and Raft Association
- Transmembrane domain of influenza virus neuraminidase, a type II protein, possesses an apical sorting signal in polarized MDCK cells.