title: Expression of SERPINA3s in cattle: focus on bovSERPINA3-7 reveals specific involvement in skeletal muscle.
abstract: α₁-Antichymotrypsin is encoded by the unique SERPINA3 gene in humans, while it is encoded by a cluster of eight closely related genes in cattle. BovSERPINA3 proteins present a high degree of similarity and significant divergences in the reactive centre loop (RCL) domains which are responsible for the antiprotease activity. In this study, we analysed their expression patterns in a range of cattle tissues. Even if their expression is ubiquitous, we showed that the expression levels of each serpin vary in different tissues of 15-month-old Charolais bulls. Our results led us to focus on bovSERPINA3-7, one of the two most divergent members of the bovSERPINA3 family. Expression analyses showed that bovSERPINA3-7 protein presents different tissue-specific patterns with diverse degrees of N-glycosylation. Using a specific antibody raised against bovSERPINA3-7, Western blot analysis revealed a specific 96 kDa band in skeletal muscle. BovSERPINA3-7 immunoprecipitation and mass spectrometry revealed that this 96 kDa band corresponds to a complex of bovSERPINA3-7 and creatine kinase M-type. Finally, we reported that the bovSERPINA3-7 protein is present in slow-twitch skeletal myofibres. Precisely, bovSERPINA3-7 specifically colocalized with myomesin at the M-band region of sarcomeres where it could interact with other components such as creatine kinase M-type. This study opens new prospects on the bovSERPINA3-7 function in skeletal muscle and promotes opportunities for further understanding of the physiological role(s) of serpins.
authors.forename: Antoine
authors.initials: A
authors.lastname: Péré-Brissaud
authors.forename: Xavier
authors.initials: X
authors.lastname: Blanchet
authors.forename: Didier
authors.initials: D
authors.lastname: Delourme
authors.forename: Patrick
authors.initials: P
authors.lastname: Pélissier
authors.forename: Lionel
authors.initials: L
authors.lastname: Forestier
authors.forename: Arnaud
authors.initials: A
authors.lastname: Delavaud
authors.forename: Nathalie
authors.initials: N
authors.lastname: Duprat
authors.forename: Brigitte
authors.initials: B
authors.lastname: Picard
authors.forename: Abderrahman
authors.initials: A
authors.lastname: Maftah
authors.forename: Laure
authors.initials: L
authors.lastname: Brémaud
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D064211:Connectin / Q000378:metabolism; D052283:Creatine Kinase, MM Form / Q000737:chemistry / Q000378:metabolism; D005786:Gene Expression Regulation; D006031:Glycosylation; D047468:Immunoprecipitation; D008297:Male; D013058:Mass Spectrometry; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism*; D011485:Protein Binding; D014176:Protein Biosynthesis; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D016415:Sequence Alignment; D015843:Serpins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*
chemical_list: D064211:Connectin; D011994:Recombinant Proteins; C402207:SERPINA3 protein, Bos taurus; D015843:Serpins; D052283:Creatine Kinase, MM Form