title: Neuraminidase of Mycoplasma synoviae desialylates heavy chain of the chicken immunoglobulin G and glycoproteins of chicken tracheal mucus.
abstract: Major poultry pathogens, Mycoplasma gallisepticum and Mycoplasma synoviae share several genes, including nanH that encodes their sialidases (neuraminidases). Previous studies have shown considerable differences in neuraminidase enzymatic activity (NEAC) in M. synoviae strains and NEAC absence in individual cultures of two strains, ULB 925 and ULB 9122. The present study shows that the cultures lacking NEAC did not express NanH neuraminidase detectable by specific antibodies. In cultures of M. synoviae ULB 925 and ULB 9122, which lacked NEAC and detectable NanH, deletions of a single adenine in different nanH regions of each strain created translational frameshifts resulting in TAA (UAA) stop codons and premature termination of translation. ULB 925 and ULB 9122 with such nanH mutations did not desialylate reference fetuin and transferrin or chicken glycoproteins that M. synoviae strains with NEAC efficiently desialylated. They desialylated several chicken serum glycoproteins with SAα(2-6)gal moieties, including the immunoglobulin G heavy chain. Neuraminidase inhibitor 2,3-didehydro-2-deoxy-N-acetylneuraminic acid inhibited such desialylation otherwise caused by M. synoviae WVU 1853 neuraminidase. WVU 1853 also cleaved sialic acid from SAα(2-3)gal moieties from glycoproteins of mucus from chicken tracheas. This is the first demonstration that M. synoviae desialylates glycoproteins of its host.
authors.affiliation: Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Groblje 3, 1230, Domžale, Slovenia.
authors.forename: Rebeka Lucijana
authors.initials: RL
authors.lastname: Berčič
authors.forename: Ivanka
authors.initials: I
authors.lastname: Cizelj
authors.forename: Daliborka
authors.initials: D
authors.lastname: Dušanić
authors.forename: Mojca
authors.initials: M
authors.lastname: Narat
authors.forename: Olga
authors.initials: O
authors.lastname: Zorman-Rojs
authors.forename: Peter
authors.initials: P
authors.lastname: Dovč
authors.forename: Dušan
authors.initials: D
authors.lastname: Benčina
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial; D002645:Chickens; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D007142:Immunoglobulin gamma-Chains / Q000235:genetics / Q000378:metabolism*; D009093:Mucus / Q000737:chemistry*; D045805:Mycoplasma synoviae / Q000201:enzymology*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009439:Neuraminidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014132:Trachea / Q000378:metabolism
chemical_list: D000907:Antibodies, Bacterial; D006023:Glycoproteins; D007142:Immunoglobulin gamma-Chains; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid