|
Basic Characteristics of Mutations
|
|
Mutation Site
|
W23C |
|
Mutation Site Sentence
|
It was found that mutation of transmembrane domain residues Ser(9), Ser(12), Phe(13), Ser(16), His(19), and Trp(23) to cysteine were most disruptive for ion channel function. |
|
Mutation Level
|
Amino acid level |
|
Mutation Type
|
Nonsynonymous substitution |
|
Gene/Protein/Region
|
M2 |
|
Standardized Encoding Gene
|
M
|
|
Genotype/Subtype
|
- |
|
Viral Reference
|
-
|
|
Functional Impact and Mechanisms
|
|
Disease
|
Influenza B
|
|
Immune
|
- |
|
Target Gene
|
-
|
|
Clinical and Epidemiological Correlations
|
|
Clinical Information
|
- |
|
Treatment
|
- |
|
Location
|
- |
|
Literature Information
|
|
PMID
|
18408016
|
|
Title
|
Identification of the pore-lining residues of the BM2 ion channel protein of influenza B virus
|
|
Author
|
Ma C,Soto CS,Ohigashi Y,Taylor A,Bournas V,Glawe B,Udo MK,Degrado WF,Lamb RA,Pinto LH
|
|
Journal
|
The Journal of biological chemistry
|
|
Journal Info
|
2008 Jun 6;283(23):15921-31
|
|
Abstract
|
The influenza B virus BM2 proton-selective ion channel is essential for virus uncoating, a process that occurs in the acidic environment of the endosome. The BM2 channel causes acidification of the interior of the virus particle, which results in dissociation of the viral membrane protein from the ribonucleo-protein core. The BM2 protein is similar to the A/M2 protein ion channel of influenza A virus (A/M2) in that it contains an HXXXW motif. Unlike the A/M2 protein, the BM2 protein is not inhibited by the antiviral drug amantadine. We used mutagenesis to ascertain the pore-lining residues of the BM2 ion channel. The specific activity (relative to wild type), reversal voltage, and susceptibility to modification by (2-aminoethyl)-methane thiosulfonate and N-ethylmaleimide of cysteine mutant proteins were measured in oocytes. It was found that mutation of transmembrane domain residues Ser(9), Ser(12), Phe(13), Ser(16), His(19), and Trp(23) to cysteine were most disruptive for ion channel function. These cysteine mutants were also most susceptible to (2-aminoethyl)-methane thiosulfonate and N-ethylmaleimide modification. Furthermore, considerable amounts of dimer were formed in the absence of oxidative reagents when cysteine was introduced at positions Ser(9), Ser(12), Ser(16), or Trp(23). Based on these experimental data, a BM2 transmembrane domain model is proposed. The presence of polar residues in the pore is a probable explanation for the amantadine insensitivity of the BM2 protein and suggests that related but more polar compounds might serve as useful inhibitors of the protein.
|
|
Sequence Data
|
-
|
|
|