title: Identification of antithrombin-modulating genes. Role of LARGE, a gene encoding a bifunctional glycosyltransferase, in the secretion of proteins?
abstract: The haemostatic relevance of antithrombin together with the low genetic variability of SERPINC1, and the high heritability of plasma levels encourage the search for modulating genes. We used a hypothesis-free approach to identify these genes, evaluating associations between plasma antithrombin and 307,984 polymorphisms in the GAIT study (352 individuals from 21 Spanish families). Despite no SNP reaching the genome wide significance threshold, we verified milder positive associations in 307 blood donors from a different cohort. This validation study suggested LARGE, a gene encoding a protein with xylosyltransferase and glucuronyltransferase activities that forms heparin-like linear polysaccharides, as a potential modulator of antithrombin based on the significant association of one SNPs, rs762057, with anti-FXa activity, particularly after adjustment for age, sex and SERPINC1 rs2227589 genotype, all factors influencing antithrombin levels (p = 0.02). Additional results sustained this association. LARGE silencing inHepG2 and HEK-EBNA cells did not affect SERPINC1 mRNA levels but significantly reduced the secretion of antithrombin with moderate intracellular retention. Milder effects were observed on α1-antitrypsin, prothrombin and transferrin. Our study suggests LARGE as the first known modifier of plasma antithrombin, and proposes a new role for LARGE in modulating extracellular secretion of certain glycoproteins.
authors.affiliation: Centro Regional de Hemodonación, Servicio de Hematología y Oncología Médica, HU Morales Meseguer, Regional Campus of International Excellence Campus Mare Nostrum University of Murcia, Murcia, Spain.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: de la Morena-Barrio
authors.forename: Alfonso
authors.initials: A
authors.lastname: Buil
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Antón
authors.forename: Irene
authors.initials: I
authors.lastname: Martínez-Martínez
authors.forename: Antonia
authors.initials: A
authors.lastname: Miñano
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gutiérrez-Gallego
authors.forename: José
authors.initials: J
authors.lastname: Navarro-Fernández
authors.forename: Sonia
authors.initials: S
authors.lastname: Aguila
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Souto
authors.forename: Vicente
authors.initials: V
authors.lastname: Vicente
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Soria
authors.forename: Javier
authors.initials: J
authors.lastname: Corral
mesh_terms: D000328:Adult; D000991:Antithrombins / Q000097:blood / Q000378:metabolism*; D016022:Case-Control Studies; D015951:Factor Xa / Q000378:metabolism; D005260:Female; D020868:Gene Silencing; D056726:Genetic Association Studies; D055106:Genome-Wide Association Study; D054794:Glycomics; D006023:Glycoproteins / Q000378:metabolism*; D057809:HEK293 Cells; D006239:Haplotypes / Q000235:genetics; D056945:Hep G2 Cells; D006801:Humans; D008297:Male; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics*; D040901:Proteomics; D015203:Reproducibility of Results
chemical_list: D000991:Antithrombins; D006023:Glycoproteins; C117674:LARGE1 protein, human; D017351:N-Acetylglucosaminyltransferases; D015951:Factor Xa