Type XVII collagen (BP 180) in the developing avian cornea.
OBJECTIVE
Previous sequence analyses of hemidesmosomal BP 180/collagen XVII cDNA from human skin and of a similar chicken corneal cDNA showed some similarities, but major differences as well. The authors examined whether, in one species, the same mRNA is present in cornea and skin. They also studied the developmental expression of the molecule and compared it to the transmembrane hemidesmosome component, alpha 6 beta 4 integrin, and to the formation of hemidesmosomes themselves.


METHODS
Cornea and skin BP 180/collagen XVII cDNAs were cloned by reverse transcription-polymerase chain reaction (RT-PCR) and sequenced. Developmental expression was evaluated by quantitative RT-PCR, immunoblotting, and immunofluorescence microscopy. alpha 6 beta 4 integrin was evaluated by immunofluorescence microscopy, and hemidesmosome formation was assessed by electron microscopy.


RESULTS
The same alpha 1 (XVII) collagen/BP 180 mRNA is present in cornea and skin. The appearance of alpha 1 (XVII) collagen mRNA and protein shows similar temporal patterns of expression, with changes in the mRNA preceding those of the protein by approximately 2 days. The appearance of mature hemidesmosomes lags still further. Immunofluorescence histochemistry of alpha 1 (XVII) collagen and alpha 6 beta 4 integrin shows that their developmental appearance is regulated closely.


CONCLUSIONS
The differences between human BP 180/collagen XVII and the chicken corneal molecule represent species divergence. The appearance of alpha 1 (XVII) collagen mRNA and protein is regulated closely, with the protein lagging. Mature hemidesmosomes, once present, have a low turnover rate. The developmental appearance of alpha 1 (XVII) collagen and alpha 6 beta 4 integrin are regulated closely. However, the component responsible for initiating hemidesmosome formation remains unknown.
Gordon
M K
MK
Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, MA 02111, USA.
Fitch
J M
JM
Foley
J W
JW
Gerecke
D R
DR
Linsenmayer
C
C
Birk
D E
DE
Linsenmayer
T F
TF
D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis / Q000235:genetics; D001324:Autoantigens / Q000096:biosynthesis* / Q000235:genetics; D015153:Blotting, Western; D002352:Carrier Proteins; D002642:Chick Embryo; D003094:Collagen / Q000096:biosynthesis* / Q000235:genetics; D003315:Cornea / Q000196:embryology / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D017931:DNA Primers / Q000737:chemistry; D003896:Desmosomes / Q000378:metabolism / Q000648:ultrastructure; D000071821:Dystonin; D019084:Fluorescent Antibody Technique, Indirect; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D039161:Integrin alpha6beta4; D016023:Integrins / Q000096:biosynthesis / Q000235:genetics; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D012867:Skin / Q000196:embryology / Q000378:metabolism; D014158:Transcription, Genetic; D000097805:Collagen Type XVII
D000954:Antigens, Surface; D001324:Autoantigens; D002352:Carrier Proteins; D003094:Collagen; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D000071821:Dystonin; D039161:Integrin alpha6beta4; D016023:Integrins; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D012333:RNA, Messenger; D000097805:Collagen Type XVII; C486268:DST protein, human