The hemagglutinin cleavability of a virulent avian influenza virus by subtilisin-like endoproteases is influenced by the amino acid immediately downstream of the cleavage site.

Abstract

Many viral membrane glycoproteins are post-translationally processed by intracellular endoproteases such as subtilisin-like proteases. These proteases recognize a cleavage site sequence comprising basic amino acids positioned upstream of the cleavage site of the viral proteins. Here, we mutated the glycine residue immediately downstream of the cleavage site (P1) of hemagglutinin (HA) from a virulent avian influenza virus, A/turkey/Ontario/7732/66 (H5N9) (R-R-R-K-K-R/G), to examine the effect of this mutation on its clevability. Substitution of Gly with Ile, Leu, Val, or Pro, but not Ala, Asp, Phe, His, Ser, or Thr, resulted in substantial reduction of HA cleavage by endogenous endoproteases in CV-1 cells and by vaccinia-expressed PC6 and, albeit to a lesser extent, furin. We conclude that HA cleavage by subtilisin-like proteases is influenced by the downstream P1 amino acid in the absence of upstream cleavage site sequence alterations.

• Authors: T Horimoto, Y Kawaoka
• Journal: Virology (Virology) Vol. 210 Issue 2 Pg. 466-70 (Jul 10 1995) ISSN: 0042-6822 [Print] United States
• PMID: 7618281 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Amino Acids
• Hemagglutinins, Viral
• Proprotein Convertase 5
• Serine Endopeptidases
• Subtilisins
• Furin

Topics

• Amino Acid Sequence
• Amino Acids (physiology)
• Furin
• Hemagglutinins, Viral (genetics, metabolism)
• Influenza A virus (enzymology, genetics, metabolism)
• Molecular Sequence Data
• Mutation (physiology)
• Proprotein Convertase 5
• Protein Processing, Post-Translational (genetics)
• Serine Endopeptidases (metabolism)
• Substrate Specificity
• Subtilisins (metabolism)
• Tumor Cells, Cultured
• Vaccinia virus (genetics)