title: Collagen XVII is destabilized by a glycine substitution mutation in the cell adhesion domain Col15.
abstract: Collagen XVII is a hemidesmosomal transmembrane molecule important for epithelial adhesion in the skin. It exists in two forms, as a full-length protein and as a soluble ectodomain that is shed from the keratinocyte surface by furin-mediated proteolysis. To obtain information on the conformation and the functions of this unusual collagen, its largest collagenous domain, Col15, was expressed in a eukaryotic episomal expression system and purified by DEAE and fast protein liquid- Mono S chromatography. The protein was triple-helical (T(m) of 26.5 degrees C) when produced in cultures containing ascorbic acid. When the vitamin supply was limited, the 4-hydroxyproline content was reduced from 74 to 9%, which, in turn, resulted in a drastic reduction of the stability of the triple helix. The glycine substitution mutation G627V associated with junctional epidermolysis bullosa, a human blistering skin disease, also had a striking effect on thermal stability of rCol15 causing partial unfolding already at 4 degrees C. Col15 promoted cell adhesion of epithelial and fibroblastic cell lines with a beta1 integrin-mediated mechanism. In concert with this, in acquired autoimmune blistering skin diseases, circulating IgG and IgA autoantibodies were found to target rCol15r.
authors.affiliation: Department of Dermatology, University of Münster, 48149 Münster, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Tasanen
authors.forename: J A
authors.initials: JA
authors.lastname: Eble
authors.forename: M
authors.initials: M
authors.lastname: Aumailley
authors.forename: H
authors.initials: H
authors.lastname: Schumann
authors.forename: J
authors.initials: J
authors.lastname: Baetge
authors.forename: H
authors.initials: H
authors.lastname: Tu
authors.forename: P
authors.initials: P
authors.lastname: Bruckner
authors.forename: L
authors.initials: L
authors.lastname: Bruckner-Tuderman
mesh_terms: D019943:Amino Acid Substitution; D001324:Autoantigens / Q000737:chemistry* / Q000235:genetics*; D002352:Carrier Proteins; D002448:Cell Adhesion; D002942:Circular Dichroism; D003094:Collagen / Q000737:chemistry* / Q000235:genetics*; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D005998:Glycine / Q000737:chemistry / Q000235:genetics; D006801:Humans; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D017354:Point Mutation; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D000097805:Collagen Type XVII
chemical_list: D001324:Autoantigens; D002352:Carrier Proteins; D003094:Collagen; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D005998:Glycine; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D000097805:Collagen Type XVII; C486268:DST protein, human