” † †† Polysialic acid is a cellular receptor for human adenovirus 52
In a recent issue of PNAS, Annasara Lenman and coworkers from UmeŚ University report that polysialic acid is a receptor for human adenovirus (HAdV) 52. This virus, which together with HAdV 40 and 41 is associated with acute gastroenteritis (GE), has two different fibers, one long and one short. Previously, Lenman et al. demonstrated that the long fiber knob utilizes CAR (coxsackie and adenovirus receptor) for binding. In the present paper, they show by glycan arrays and cellular studies that the knob of the short fiber interacts electrostatically with polysialic acid on target cells. This novel finding increases understanding of the biological functions of polysialic acid, and of protein-carbohydrate interactions during adenoviral cell entry.
Sialylated Voltage-Dependent Ca2+ Channel Binds Hemagglutinin and Mediates Influenza A Virus Entry into Mammalian Cells
Influenza A virus (IAV) binds to and enter cells through hemagglutinin binding to sialic acid (SA)-containing cell surface molecules. Until now, such SA-carrying molecules have been largely unknown. It has been known that IAV entry and infection is associated with an altered, intracellular calcium concentration, which is regulated by calcium channel proteins. Voltage-dependent calcium channels (VDCCs) regulate calcium transport in a SA-dependent manner. Such observations allowed Fujioka et al to identify VDCC as cellular receptors for IAV. VDCC knockdown as well as calcium channel blockers inhibit IAV replication, and proper sialylation of VDCC is required for receptor function. This work adds knowledge about IAV life cycle and presents VDCCs as a novel targets for antiviral drugs.