title: Ultrastructural defects of collagen VI filaments in an Ullrich syndrome patient with loss of the alpha3(VI) N10-N7 domains.
abstract: Ultrastructural alterations of collagen VI in cultured fibroblasts and reduced collagen VI immunostaining in the papillary dermis and endomysium were detected in a patient with a mild form of Ullrich congenital muscular dystrophy caused by a COL6A3 gene mutation. The patient had been previously demonstrated to express an alpha3(VI) chain shorter than normal due to skipping of the mutated exon. We show that collagen VI filaments are not organized in a normal network in the extracellular matrix secreted by patient's cultured fibroblasts. Moreover, we demonstrate that in this patient the alpha3(VI) chain is produced in lower amounts and it is almost exclusively represented by the shorter, alternatively spliced N6-C5 isoform. These results suggest that different alpha3(VI) chain isoforms, containing also domains of the N10-N7 region, are required for assembling a proper collagen VI network in the extracellular matrix.
authors.affiliation: ITOI-CNR, Unit of Bologna c/o IOR, Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Squarzoni
authors.forename: Patrizia
authors.initials: P
authors.lastname: Sabatelli
authors.forename: Natascha
authors.initials: N
authors.lastname: Bergamin
authors.forename: Pascale
authors.initials: P
authors.lastname: Guicheney
authors.forename: Ercan
authors.initials: E
authors.lastname: Demir
authors.forename: Luciano
authors.initials: L
authors.lastname: Merlini
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lattanzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Ognibene
authors.forename: Cristina
authors.initials: C
authors.lastname: Capanni
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Mattioli
authors.forename: Marta
authors.initials: M
authors.lastname: Columbaro
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonaldo
authors.forename: Nadir Mario
authors.initials: NM
authors.lastname: Maraldi
mesh_terms: D002478:Cells, Cultured; D024142:Collagen Type VI / Q000235:genetics / Q000648:ultrastructure; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D018482:Muscle, Skeletal / Q000166:cytology; D049288:Muscular Dystrophies, Limb-Girdle / Q000235:genetics / Q000473:pathology; D009154:Mutation; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012867:Skin / Q000166:cytology
chemical_list: D024142:Collagen Type VI; D020033:Protein Isoforms