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Updated: Jun 15, 2026
Cell Surface Receptor Identification Using Genome-Scale CRISPR/Cas9 Genetic Screens
Published on: June 6, 2020
Identification of β4GALNT2 as an anti-hPIV3 factor through genome-wide CRISPR/Cas9 library screening
Xuesheng Wu1, Rutger D Luteijn1, Estefanía Lozano-Andrés2,3
1Section Virology, Division Infectious Diseases and Immunology, Department Biomolecular Health Sciences, Faculty Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Abstract:
Human respirovirus 3 (also known as human parainfluenza virus 3; hPIV3) is a major cause of severe acute respiratory infections in vulnerable populations. Here we conducted a genome-wide CRISPR/Cas9 library screen to identify key host factors for hPIV3 infection. In addition to identifying several host proteins involved in glycosylation as proviral factors, we identified β-1,4-N-Acetyl-Galactosaminyltransferase 2 (β4GALNT2) as a potent restriction factor. Further investigation demonstrated that the addition of a GalNAc residue to α2-3-sialylated glycans by β4GALNT2, resulting in the Sda glycotope, disrupted the interaction between the viral hemagglutinin-neuraminidase (HN) attachment protein and sialoglycan receptors. Specifically, the additional GalNAc residue interfered with the interaction of residue W371 in HN with sub-terminal glycan moieties. β4GALNT2-mediated Sda epitope expression also negatively affected infection by other respiroviruses, with the strongest effect being observed for hPIV3.
Insights
Human parainfluenza virus 3 (hPIV3) causes severe respiratory infections. Researchers found that the enzyme β4GALNT2 restricts hPIV3 by altering cell surface glycans, blocking viral attachment and infection.
Area of Science:
- Virology
- Glycobiology
- Molecular Biology
Background:
- Human parainfluenza virus 3 (hPIV3) is a significant pathogen causing severe respiratory illness, particularly in vulnerable groups.
- Understanding host-virus interactions is crucial for developing effective antiviral strategies.
Purpose of the Study:
- To identify host factors essential for hPIV3 infection using a genome-wide CRISPR/Cas9 screen.
- To elucidate the mechanism by which identified host factors regulate hPIV3 entry.
Main Methods:
- Genome-wide CRISPR/Cas9 library screen to identify host proviral and restriction factors for hPIV3.
- Biochemical and cell-based assays to investigate the role of β-1,4-N-Acetyl-Galactosaminyltransferase 2 (β4GALNT2) in hPIV3 infection.
- Analysis of viral hemagglutinin-neuraminidase (HN) protein interaction with modified sialoglycan receptors.
Main Results:
- The screen identified host proteins involved in glycosylation as proviral factors.
- β-1,4-N-Acetyl-Galactosaminyltransferase 2 (β4GALNT2) was identified as a potent restriction factor for hPIV3.
- β4GALNT2 mediates the addition of GalNAc residues to sialylated glycans, forming the Sdª glycotope.
- The Sdª glycotope disrupts the binding of the hPIV3 HN protein to sialoglycan receptors by interfering with interactions involving residue W371.
- β4GALNT2-mediated Sdª expression also restricted other respiroviruses, with the most pronounced effect on hPIV3.
Conclusions:
- β4GALNT2 acts as a restriction factor against hPIV3 by modifying cell surface glycans.
- The Sdª glycotope formed by β4GALNT2 inhibits hPIV3 attachment and infection.
- Targeting β4GALNT2 or the Sdª epitope may represent a novel therapeutic strategy against hPIV3 and other respiroviruses.
