Mutations in the N Termini of Herpes Simplex Virus Type 1 and 2 gDs Alter Functional Interactions with the Entry/Fusion Receptors HVEM, Nectin-2, and 3-O-Sulfated Heparan Sulfate but Not with Nectin-1
AUTOR(ES)
Yoon, Miri
FONTE
American Society for Microbiology
RESUMO
Multiple cell surface molecules (herpesvirus entry mediator [HVEM], nectin-1, nectin-2, and 3-O-sulfated heparan sulfate) can serve as entry receptors for herpes simplex virus type 1 (HSV-1) or HSV-2 and also as receptors for virus-induced cell fusion. Viral glycoprotein D (gD) is the ligand for these receptors. A previous study showed that HVEM makes contact with HSV-1 gD at regions within amino acids 7 to 15 and 24 to 32 at the N terminus of gD. In the present study, amino acid substitutions and deletions were introduced into the N termini of HSV-1 and HSV-2 gDs to determine the effects on interactions with all of the known human and mouse entry/fusion receptors, including mouse HVEM, for which data on HSV entry or cell fusion were not previously reported. A cell fusion assay was used to assess functional activity of the gD mutants with each entry/fusion receptor. Soluble gD:Fc hybrids carrying each mutation were tested for the ability to bind to cells expressing the entry/fusion receptors. We found that deletions overlapping either or both of the HVEM contact regions, in either HSV-1 or HSV-2 gD, severely reduced cell fusion and binding activity with all of the human and mouse receptors except nectin-1. Amino acid substitutions described previously for HSV-1 (L25P, Q27P, and Q27R) were individually introduced into HSV-2 gD and, for both serotypes, were found to be without effect on cell fusion and the binding activity for nectin-1. Each of these three substitutions in HSV-1 gD enhanced fusion with cells expressing human nectin-2 (ordinarily low for wild-type HSV-1 gD), but the same substitutions in HSV-2 gD were without effect on the already high level of cell fusion observed with the wild-type protein. The Q27P or Q27R substitution in either HSV-1 and HSV-2 gD, but not the L25P substitution, significantly reduced cell fusion and binding activity for both human and mouse HVEM. Each of the three substitutions in HSV-1 gD, as well as the deletions mentioned above, reduced fusion with cells bearing 3-O-sulfated heparan sulfate. Thus, the N terminus of HSV-1 or HSV-2 gD is not necessary for functional interactions with nectin-1 but is necessary for all of the other receptors tested here. The sequence of the N terminus determines whether nectin-2 or 3-O-sulfated heparan sulfate, as well as HVEM, can serve as entry/fusion receptors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=187404Documentos Relacionados
- Differences in the N Termini of Herpes Simplex Virus Type 1 and 2 gDs That Influence Functional Interactions with the Human Entry Receptor Nectin-2 and an Entry Receptor Expressed in Chinese Hamster Ovary Cells
- Potential Nectin-1 Binding Site on Herpes Simplex Virus Glycoprotein D
- In Vivo Role of Nectin-1 in Entry of Herpes Simplex Virus Type 1 (HSV-1) and HSV-2 through the Vaginal Mucosa
- Disruption of Adherens Junctions Liberates Nectin-1 To Serve as Receptor for Herpes Simplex Virus and Pseudorabies Virus Entry
- Swine testis cells contain functional heparan sulfate but are defective in entry of herpes simplex virus.