@article{mbs:/content/journal/jgv/10.1099/0022-1317-76-7-1623, author = "Miethke, Annegret and Keil, Günther M. and Weiland, Frank and Mettenleiter, Thomas C.", title = "Unidirectional complementation between glycoprotein B homologues of pseudorabies virus and bovine herpesvirus 1 is determined by the carboxy-terminal part of the molecule", journal= "Journal of General Virology", year = "1995", volume = "76", number = "7", pages = "1623-1635", doi = "https://doi.org/10.1099/0022-1317-76-7-1623", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-76-7-1623", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "The most highly conserved glycoproteins in herpesviruses, homologues of glycoprotein B (gB) of herpes simplex virus, have been shown to play essential roles in membrane fusion during penetration and direct cell-to-cell spread of herpes virions. In studies aimed at assessing whether sequence conservation is reflected in the conservation of functional properties, we previously showed that bovine herpesvirus 1 (BHV-1) gB was able to functionally complement a gB− PrV mutant. To analyse in detail the function of gB in BHV-1, and to be able to test for reciprocal complementation between pseudorabies virus (PrV) and BHV-1 gB, we isolated a gB− BHV-1 mutant on a cell line stably expressing BHV-1 gB. Functional analysis showed that BHV-1 gB was essential for penetration as well as for direct cell-to-cell spread of BHV-1, indicating similar functions for PrV and BHV-1 gB. However, PrV gB was unable to complement plaque formation, i.e. direct cell-to-cell spread, or penetration of gB− BHV-1 virions despite its incorporation into the virion envelope. Analysis of cell lines expressing chimeric gB molecules composed of PrV and BHV-1 gB showed that plaque formation of both gB− mutants was complemented when the carboxy-terminal half of the chimeric gB was derived from BHV-1 gB and the amino-terminal half from PrV gB. In the opposite case, unidirectional complementation occurred. Although the chimeric molecules were generally less efficient in complementing infectivity of free virions, a similar complementation pattern was observed. In summary, our data show a unidirectional pattern of transcomplementation between the gB glycoproteins of PrV and BHV-1. This indicates that these proteins are functionally related but not identical. The unidirectional transcomplementation pattern was determined by the provenance of the carboxy-terminal half in chimeric gB proteins indicating that regions which are important for gB function but differ between PrV and BHV-1 reside in this part of gB.", }