Mutations in the conserved carboxy-terminal hydrophobic region of glycoprotein gB affect infectivity of herpes simplex virus.

Glycoprotein gB is the most highly conserved glycoprotein in the herpesvirus family and plays a critical role in virus entry and fusion. Glycoprotein gB of herpes simplex virus type 1 contains a hydrophobic stretch of 69 aa near the carboxy terminus that is essential for its biological activity. To determine the role(s) of specific amino acids in the carboxy-terminal hydrophobic region, a number of amino acids were mutagenized that are highly conserved in this region within the gB homologues of the family HERPESVIRIDAE: Three conserved residues in the membrane anchor domain, namely A786, A790 and A791, as well as amino acids G743, G746, G766, G770 and P774, that are non-variant in Herpesviridae, were mutagenized.

Structure, expression and phylogenetic analysis of the glycoprotein gene of Cocal virus.

A cDNA copy of the mRNA of the glycoprotein G of Cocal virus, a rhabdovirus, has been cloned, sequenced and expressed in mammalian cells. The deduced amino acid sequence shows a typical transmembrane glycoprotein, 512 amino acids in length, containing two potential N-linked glycosylation sites. The amino acid sequence showed a high degree of identity with that of the prototype vesicular stomatitis virus serotype Indiana [VSV (IND)] G protein.

Mutations in a carboxy-terminal region of vesicular stomatitis virus glycoprotein G that affect membrane fusion activity.

The envelope glycoprotein G of vesicular stomatitis virus induces membrane fusion at acidic pH. A highly conserved amino terminal region spanning residues 123 to 137 has previously been identified as an internal fusion domain. Here we have substituted specific amino acids within a carboxy terminal region, conserved in five vesiculoviruses encompassing residues 395 to 418, and studied the effect of these mutations on membrane fusion at acid pH and pH-dependent conformational change.

Influence of membrane anchoring and cytoplasmic domains on the fusogenic activity of vesicular stomatitis virus glycoprotein G.

Chimeric proteins in which the transmembrane anchoring sequence (TM) or both the TM and the cytoplasmic tail (CT) of vesicular stomatitis virus glycoprotein G were replaced with corresponding domains of viral or cellular integral membrane proteins were used to examine the influence of these domains on acidic-pH-induced membrane fusion by G protein. The TM and CT of G were also replaced with the lipid anchor glycosylphosphatidylinositol. Hybrids containing foreign TM or TM and CT sequences were fusogenic at acidic pH but glycosylphosphatidylinositol-anchored G was nonfusogenic at acidic pH.