α-Dystroglycan can mediate arenavirus infection in the absence of β-dystroglycan

AbstractDystroglycan (DG) is a highly versatile cell surface molecule that provides a molecular link between the extracellular matrix (ECM) and the actin-based cytoskeleton. Encoded by a single gene, DG is posttranslationally processed to form α-DG, a peripheral protein identified as the cellular receptor for lymphocytic choriomeningitis virus (LCMV) and Lassa fever virus (LFV), and the membrane-spanning subunit β-DG. The link of β-DG to the actin-based cytoskeleton and its association with the cellular signal transduction network suggest that it may function as an essential cofactor for the activity of α-DG as a virus receptor. To address this issue, we constructed a deletion mutant lacking the cytoplasmic domain of β-DG and a C-terminal fusion between α-DG and the transmembrane domain of PDGF receptor. Both mutants were functional as virus receptors, indicating that β-DG does not act as a cofactor with α-DG for arenavirus binding and entry. These observations are in agreement with the fact that LCMV infection is independent from the structural integrity of the actin-based cytoskeleton and suggest that α-DG functions primarily in the attachment of arenaviruses to the cell surface