Collagen XVII is destabilized by a glycine substitution mutation in the cell adhesion domain Col15.
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.
Tasanen
K
K
Department of Dermatology, University of Münster, 48149 Münster, Germany.
Eble
J A
JA
Aumailley
M
M
Schumann
H
H
Baetge
J
J
Tu
H
H
Bruckner
P
P
Bruckner-Tuderman
L
L
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
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