title: Cleavage site and Ectodomain of HA2 sub-unit sequence of three equine influenza virus isolated in Morocco.
abstract: BACKGROUND
  The equine influenza (EI) is an infectious and contagious disease of the upper respiratory tract of horses. Two outbreaks were notified in Morocco during 1997 and 2004 respectively in Nador and Essaouira. The aims of the present study concern the amino acids sequences comparison with reference strain A/equine/Miami/1963(H3N8) of the HA2 subunit including the cleavage site of three equine influenza viruses (H3N8) isolated in Morocco: A/equine/Nador/1/1997(H3N8), A/equine/Essaouira/2/2004 (H3N8) and A/equine/Essaouira/3/2004 (H3N8).
  
  
  RESULTS
  The obtained results demonstrated that the substitutions were located at Ectodomain (ED) and transmembrane domain (TD), and they have only one arginine in cleavage site (HA1-PEKQI-R329-GI-HA2). In the Ectodomain, the mutation N/1542/T deleted the NGT glycosylation site at position 154 for both strains A/equine/Essaouira/2/2004(H3N8) and A/equine/Essaouira/3/2004(H3N8). Except for mutation D/1602/Y of the A/equine/Nador/1/1997(H3N8) strain, the other mutations were involved in non conserved sites. While the transmembrane domain (TM) of the strain A/equine/Essaouira/3/2004(H3N8) exhibits a substitution at residue C/1992/F. For the A/equine/Nador/1/1997(H3N8) strain the HA2 shows a mutation at residue M/2072/L. Three Moroccan strains reveals a common substitution at the residue E/2112/Q located between transmembrane domain TM and the cytoplasmic domain (CD).
  
  
  CONCLUSIONS
  The given nature virulence of three Moroccan strains, the identified and reported mutations certainly played a permissive role of infection viral process.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Boukharta
authors.forename: Fathiah
authors.initials: F
authors.lastname: Zakham
authors.forename: Nadia
authors.initials: N
authors.lastname: Touil
authors.forename: Mehdi
authors.initials: M
authors.lastname: Elharrak
authors.affiliation: University Hassan II, Faculty of Sciences and Techniques, Mohammedia-Casablanca, Laboratory of Virology, Microbiology and Quality/ETB, Mohammedia BP 146, (20650), Morocco. m.ennaji@yahoo.fr.
authors.forename: Moulay Mustapha
authors.initials: MM
authors.lastname: Ennaji
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004196:Disease Outbreaks; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000145:classification / Q000235:genetics*; D006734:Horse Diseases / Q000453:epidemiology* / Q000821:virology; D006736:Horses; D053123:Influenza A Virus, H3N8 Subtype / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009018:Morocco / Q000453:epidemiology; D009154:Mutation; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000145:classification / Q000235:genetics*; D059748:Proteolysis; D016415:Sequence Alignment
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D021122:Protein Subunits