Characterization of an alternate form of Newcastle disease virus fusion protein
Graduate School of Biomedical Sciences; Program in Immunology and Virology; Department of Molecular Genetics and Microbiology; Department of Biochemistry and Molecular Pharmacology
Medical Subject Headings
Amino Acid Sequence; Animals; Antibodies, Viral; COS Cells; Cercopithecus aethiops; Chickens; Molecular Sequence Data; Newcastle disease virus; Protein Isoforms; Rabbits; Recombinant Proteins; Transfection; Viral Fusion Proteins
Life Sciences | Medicine and Health Sciences
The sequence and structure of the Newcastle disease virus (NDV) fusion (F) protein are consistent with its classification as a type 1 glycoprotein. We have previously reported, however, that F protein can be detected in at least two topological forms with respect to membranes in both a cell-free protein synthesizing system containing membranes and infected COS-7 cells (J. Virol. 77:1951-1963, 2003). One form is the classical type 1 glycoprotein, while the other is a polytopic form in which approximately 200 amino acids of the amino-terminal end as well as the cytoplasmic domain (CT) are translocated across membranes. Furthermore, we detected CT sequences on surfaces of F protein-expressing cells, and antibodies specific for these sequences inhibited red blood cell fusion to hemagglutinin-neuraminidase and F protein-expressing cells, suggesting a role for surface-expressed CT sequences in cell-cell fusion. Extending these findings, we have found that the alternate form of the F protein can also be detected in infected and transfected avian cells, the natural host cells of NDV. Furthermore, the alternate form of the F protein was also found in virions released from both infected COS-7 cells and avian cells by Western analysis. Mass spectrometry confirmed its presence in virions released from avian cells. Two different polyclonal antibodies raised against sequences of the CT domain of the F protein slowed plaque formation in both avian and COS-7 cells. Antibody specific for the CT domain also inhibited single-cycle infections, as detected by immunofluorescence of viral proteins in infected cells. The potential roles of this alternate form of the NDV F protein in infection are discussed.
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Citation: J Virol. 2005 Sep;79(18):11660-70. Link to article on publisher's site
Journal of virology
Pantua, Homer Dadios; McGinnes, Lori; Leszyk, John D.; and Morrison, Trudy G., "Characterization of an alternate form of Newcastle disease virus fusion protein" (2005). GSBS Student Publications. 930.