Topological changes in the transmembrane domains of hepatitis C virus envelope glycoproteins
AUTOR(ES)
Cocquerel, Laurence
FONTE
Oxford University Press
RESUMO
Hepatitis C virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C virus envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=125386Documentos Relacionados
- Synthesis of a novel hepatitis C virus protein by ribosomal frameshift
- Intramembrane proteolysis promotes trafficking of hepatitis C virus core protein to lipid droplets
- The Transmembrane Domains of Sindbis Virus Envelope Glycoproteins Induce Cell Death
- Charged Residues in the Transmembrane Domains of Hepatitis C Virus Glycoproteins Play a Major Role in the Processing, Subcellular Localization, and Assembly of These Envelope Proteins
- Characterization of Functional Hepatitis C Virus Envelope Glycoproteins