title: A functional splice variant of the human Golgi CMP-sialic acid transporter.
abstract: The human Golgi Cytidine-5'-monophospho-N-acetylneuraminic acid (CMP-Sia) transporter SLC35A1, a member of the nucleotide sugar transporter family, translocates CMP-Sia from the cytosol into the Golgi lumen where sialyltransferases use it as donor substrate for the synthesis of sialoglycoconjugates. In 2005, we reported a novel Congenital Disorder of Glycosylation (CDG) termed CDG-IIf or SLC35A1-CDG, characterized by macrothrombocytopenia, neutropenia and complete lack of the sialyl-Lexantigen (NeuAcα2-3Galβ1-4(Fucα1-3)GlcNAc-R) on polymorphonuclear cells. This disease was caused by the presence of inactive SLC35A1 alleles. It was also found that the SLC35A1 generates additional isoforms through alternative splicing. In this work, we demonstrate that one of the reported isoforms, the del177 with exon 6 skipping, is able to maintain sialylation in HepG2 cells submitted to wt knockdown and restore sialylation to normal levels in the Chinese Hamester Ovary (CHO) cell line Lec2 mutant deficient in CMP-Sia transport. The characteristics of the alternatively spliced protein are discussed as well as therapeutic implications of this finding in CDGs caused by mutations in nucleotide sugar transporters (NSTs).
authors.affiliation: Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001,Col. Chamilpa, 62209 Cuernavaca, MOR, Cuernavaca, México.
authors.forename: Roberta
authors.initials: R
authors.lastname: Salinas-Marín
authors.affiliation: INSERM U1197, Paul Brousse Hospital, University of Paris Sud XI, 94800, Villejuif, France.
authors.forename: Rosella
authors.initials: R
authors.lastname: Mollicone
authors.affiliation: Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001,Col. Chamilpa, 62209 Cuernavaca, MOR, Cuernavaca, México. duncker@uaem.mx.
authors.forename: Iván
authors.initials: I
authors.lastname: Martínez-Duncker
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D016466:CHO Cells; D018981:Congenital Disorders of Glycosylation / Q000235:genetics / Q000378:metabolism*; D003412:Cricetulus; D006056:Golgi Apparatus / Q000235:genetics / Q000378:metabolism*; D056945:Hep G2 Cells; D006801:Humans; D033704:Nucleotide Transport Proteins / Q000096:biosynthesis* / Q000235:genetics; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics
chemical_list: D033704:Nucleotide Transport Proteins; D020033:Protein Isoforms; C491081:SLC35A1 protein, human
keywords: CDG; Lec 2; Morpholinos; SLC35A1; Sialic acid