14-3-3 sigma isoform interacts with the cytoplasmic domain of the transmembrane BP180 in keratinocytes.
The protein bullous pemphigoid antigen-2 (BPAG2/BP180/collagen type XVII) plays a key role in attachment of basal keratinocytes to epidermal basement membrane. The binding of BP180 with either integrin alpha6, integrin beta4, or bullous pemphigoid antigen-1 (BPAG1/BP230) is critical for this attachment in skin. The protein 14-3-3 sigma, also known as stratifin and a marker for epithelial cells, is a member of a highly conserved small acidic 14-3-3 protein family naturally found in all eukaryotic cells. Here, we have used a 14-3-3sigma GST pull-down screening assay and showed that sigma (sigma) isoform of the 14-3-3 protein family interacts with the cytoplasmic N-terminal domain of BP180. Analysis of a series of truncated or deleted 14-3-3sigma revealed that only intact 14-3-3sigma molecule, but not any of its fragments can interact with BP180. This finding suggests that conformation and possible dimerization of 14-3-3 sigma is essential for this interaction. Further, a BP180 co-immunoprecipitation (IP) and its reverse IP assays were conducted and the results confirmed that 14-3-3 sigma interacts with cytoplasmic domain, but not ecto-domain of the BP180. In conclusion, the finding of this study provides evidence that 14-3-3sigma isoform interacts with BP180 which is a major component of hemidesmosome involved in the attachment of epidermis to the basement membrane in skin. However, the significance of this interaction in hemidesmosome formation and/or attachment needs to be explored.
Li
Yunyuan
Y
Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
Lin
Xiaoyue
X
Kilani
Ruhangiz T
RT
Jones
Jonathan C R
JC
Ghahary
Aziz
A
D048948:14-3-3 Proteins; D001324:Autoantigens / Q000737:chemistry / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D019281:Dimerization; D000071821:Dystonin; D005092:Exonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005095:Exoribonucleases; D006801:Humans; D047468:Immunoprecipitation; D015603:Keratinocytes / Q000201:enzymology / Q000378:metabolism*; D008970:Molecular Weight; D009154:Mutation; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D000097805:Collagen Type XVII
D048948:14-3-3 Proteins; D001324:Autoantigens; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D005092:Exonucleases; D005095:Exoribonucleases; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D000097805:Collagen Type XVII; C486268:DST protein, human; C413442:SFN protein, human