Proteolytic cleavage of the murine coronavirus surface glycoprotein is not required for fusion activity - PubMed (original) (raw)

Proteolytic cleavage of the murine coronavirus surface glycoprotein is not required for fusion activity

R Stauber et al. J Gen Virol. 1993 Feb.

Abstract

A cDNA copy of the murine coronavirus [otherwise known as murine hepatitis virus (MHV)] surface (S) glycoprotein gene was isolated and expressed in DBT cells by using a recombinant vaccinia virus system. The expressed S protein induced extensive syncytium formation at neutral pH. Oligonucleotide mutagenesis was used to engineer an S protein gene in which codons for the proteolytic cleavage site, Arg-Arg-Ala-Arg-Arg, were replaced with an equal number of codons for amino acids with aliphatic or aliphatic hydroxyl side-chains. The mutated S protein was stably expressed in DBT cells and, in contrast to the wild-type protein, was not proteolytically cleaved. Nevertheless, the non-cleaved protein induced extensive syncytium formation. These results clearly indicate that the non-cleaved form of the MHV S protein is able to mediate cell membrane fusion. Thus proteolytic cleavage is not an absolute requirement for fusion activity.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances