title: The second receptor binding site of the globular head of the Newcastle disease virus hemagglutinin-neuraminidase activates the stalk of multiple paramyxovirus receptor binding proteins to trigger fusion.
abstract: The hemagglutinin-neuraminidase (HN) protein of paramyxoviruses carries out three distinct activities contributing to the ability of HN to promote viral fusion and entry: receptor binding, receptor cleavage (neuraminidase), and activation of the fusion protein. The relationship between receptor binding and fusion triggering functions of HN are not fully understood. For Newcastle disease virus (NDV), one bifunctional site (site I) on HN's globular head can mediate both receptor binding and neuraminidase activities, and a second site (site II) in the globular head is also capable of mediating receptor binding. The receptor analog, zanamivir, blocks receptor binding and cleavage activities of NDV HN's site I while activating receptor binding by site II. Comparison of chimeric proteins in which the globular head of NDV HN is connected to the stalk region of either human parainfluenza virus type 3 (HPIV3) or Nipah virus receptor binding proteins indicates that receptor binding to NDV HN site II not only can activate its own fusion (F) protein but can also activate the heterotypic fusion proteins. We suggest a general model for paramyxovirus fusion activation in which receptor engagement at site II plays an active role in F activation.
authors.affiliation: Departments of Pediatrics and of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, USA.
authors.forename: Matteo
authors.initials: M
authors.lastname: Porotto
authors.forename: Zuhair
authors.initials: Z
authors.lastname: Salah
authors.forename: Ilaria
authors.initials: I
authors.lastname: DeVito
authors.forename: Aparna
authors.initials: A
authors.lastname: Talekar
authors.forename: Samantha G
authors.initials: SG
authors.lastname: Palmer
authors.forename: Rui
authors.initials: R
authors.lastname: Xu
authors.forename: Ian A
authors.initials: IA
authors.lastname: Wilson
authors.forename: Anne
authors.initials: A
authors.lastname: Moscona
mesh_terms: D001665:Binding Sites; D002352:Carrier Proteins; D002460:Cell Line; D015707:HN Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009522:Newcastle disease virus / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D018184:Paramyxoviridae Infections / Q000378:metabolism* / Q000821:virology; D018098:Paramyxovirinae / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011991:Receptors, Virus / Q000378:metabolism*; D014760:Viral Fusion Proteins / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053586:Virus Internalization
chemical_list: D002352:Carrier Proteins; D015707:HN Protein; D011991:Receptors, Virus; D014760:Viral Fusion Proteins; D014764:Viral Proteins