ABSTRACT
α-Dystroglycan (α-DG) has been identified as a major receptor for lymphocytic choriomeningitis virus (LCMV) and Lassa virus, two Old World arenaviruses. The situation with New World arenaviruses is less clear: previous studies demonstrated that Oliveros virus also exhibited high-affinity binding to α-DG but that Guanarito virus did not. To extend these initial studies, several additional Old and New World arenaviruses were screened for entry into mouse embryonic stem cells possessing or lacking α-DG. In addition, representative viruses were further analyzed for direct binding to α-DG by means of a virus overlay protein blot assay technique. These studies indicate that Old World arenaviruses use α-DG as a major receptor, whereas, of the New World arenaviruses, only clade C viruses (i.e., Oliveros and Latino viruses) use α-DG as a major receptor. New World clade A and B arenaviruses, which include the highly pathogenic Machupo, Guanarito, Junin, and Sabia viruses, appear to use a different receptor or coreceptor for binding. Previous studies with LCMV have suggested the need for a small aliphatic amino acid at LCMV GP1 glycoprotein amino acid position 260 to allow high-affinity binding to α-DG. As reported herein, this requirement appears to be broadly applicable to the arenaviruses as determined by more extensive analysis of α-DG receptor usage and GP1 sequences of Old and New World arenaviruses. In addition, GP1 amino acid position 259 also appears to be important, since all arenaviruses showing high-affinity α-DG binding possess a bulky aromatic amino acid (tyrosine or phenylalanine) at this position.
High affinity binding of the estrogen receptor to a DNA response element does not require homodimer formation or estrogen
