The hemidesmosomal protein bullous pemphigoid antigen 1 and the integrin beta 4 subunit bind to ERBIN. Molecular cloning of multiple alternative splice variants of ERBIN and analysis of their tissue expression.
The bullous pemphigoid antigen 1 (eBPAG1) is a constituent of hemidesmosomes (HDs), cell-substrate adhesion complexes in stratified epithelia. Although its COOH terminus interacts with intermediate filaments, its NH(2) terminus is important for its recruitment into HDs. To identify proteins that interact with the NH(2) terminus of human eBPAG1, we performed a yeast two-hybrid screen, which uncovered a protein belonging to the LAP/LERP (for LRR and PDZ domain) protein family with 16 NH(2)-terminal leucine-rich repeats and a COOH-terminal PDZ domain. The gene for this LAP/LERP protein comprises at least 26 exons located on the long arm of chromosome 5. In most human tissues, several transcripts were detected differing in the coding region situated upstream of or within the PDZ domain. One of the encoded variants was found to correspond to the recently described protein ERBIN. In yeast and in vitro binding experiments, ERBIN was shown to interact not only with eBPAG1 but also with the COOH-terminal region of the cytoplasmic domain of the integrin beta4 subunit, another component of HDs. Antibodies raised against the COOH terminus showed that ERBIN is expressed in keratinocytes. In transfected epithelial cells the protein, however, was not localized in HDs but was either diffusely distributed over the cytoplasm or concentrated at the basolateral plasma membrane. Because ERBIN had been shown previously to interact with the transmembrane tyrosine kinase receptor Erb-B2, which in turn associates with the integrin beta4 subunit, we suggest that ERBIN provides a link between HD assembly and Erb-B2 receptor signaling.
Favre
B
B
Department of Dermatology, University Medical School, 1211 Geneva 14, Switzerland.
Fontao
L
L
Koster
J
J
Shafaatian
R
R
Jaunin
F
F
Saurat
J H
JH
Sonnenberg
A
A
Borradori
L
L
D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000737:chemistry / Q000378:metabolism*; D001324:Autoantigens / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D002522:Chlorocebus aethiops; D002874:Chromosome Mapping; D002895:Chromosomes, Human, Pair 5; D003001:Cloning, Molecular; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D003896:Desmosomes / Q000378:metabolism*; D000071821:Dystonin; D005091:Exons; D005260:Female; D005786:Gene Expression Regulation; D014644:Genetic Variation; D006801:Humans; D039663:Integrin beta4; D008297:Male; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D009928:Organ Specificity; D010391:Pemphigoid, Bullous / Q000235:genetics; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015183:Restriction Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae; D017384:Sequence Deletion; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms; D000097805:Collagen Type XVII
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D001324:Autoantigens; D002352:Carrier Proteins; D003094:Collagen; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D000071821:Dystonin; D039663:Integrin beta4; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D011994:Recombinant Proteins; D000097805:Collagen Type XVII; C486268:DST protein, human; C413364:ERBIN protein, human