Identification of an 80kD protein associated with the alpha 3 beta 1 integrin as a proteolytic fragment of the alpha 3 subunit: studies with human keratinocytes

Bishop, L. A., Rahman, D., Pappin, D. J., Watt, F. M. (1995) Identification of an 80kD protein associated with the alpha 3 beta 1 integrin as a proteolytic fragment of the alpha 3 subunit: studies with human keratinocytes. Cell Adhes Commun, 3 (3). pp. 243-55. ISSN 1061-5385 (Print)1023-7046 (Linking)

URL: http://www.ncbi.nlm.nih.gov/pubmed/8846025

Abstract

We have characterised a protein of approximately 80kD previously observed to co-immunoprecipitate with the alpha 3 beta 1 integrin in lysates of surface labelled human epidermalkeratinocytes. The 80kD protein only appeared when keratinocytes were harvested with trypsin/EDTA prior to lysis and a protein of similar molecular mass could be immunoprecipitated from human dermal fibroblasts following treatment of the cells with trypsin/EDTA. N terminal sequencing established that the 80kD protein had homology with the alpha 3 integrin subunit. Peptide-mass fingerprinting was used to confirm that the protein comprised the amino terminus of alpha 3 and established that the site of cleavage was after amino acid 629. The 80kD fragment could be coimmunoprecipitated with alpha 3 beta 1 using an antibody to the cytoplasmic domain of the alpha 3 subunit, showing that the fragment remained complexed with intact alpha 3 beta 1. When antibodies to the cytoplasmic and extracellular domains of alpha 3 were used to label human epidermis by immunofluorescence, the staining patterns were indistinguishable and there is therefore no evidence that proteolysis of alpha 3 plays a role in keratinocyte detachment from the basement membrane during terminal differentiation. Whether the 80kD fragment has any effects, positive or negative, on alpha 3 beta 1-mediated adhesion remains to be determined.

Item Type: Paper
Uncontrolled Keywords: Amino Acid Sequence Cell Adhesion Epidermis/chemistry Fibroblasts/chemistry Humans Infant, Newborn Integrin alpha3beta1 Integrins/analysis/chemistry/isolation & purification/ metabolism Keratinocytes/ chemistry Molecular Sequence Data Molecular Weight Peptide Fragments/analysis/ chemistry Precipitin Tests Sequence Analysis Sequence Homology, Amino Acid Skin Trypsin
Subjects: bioinformatics > genomics and proteomics > design > amino acid design
bioinformatics > genomics and proteomics > design > protein network design > peptide design
organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell division
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > fibroblasts
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > fibroblasts
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > fibroblasts

organism description > animal > mammal > primates > hominids > human
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > integrin
organs, tissues, organelles, cell types and functions > organs types and functions > skin
CSHL Authors:
Communities: CSHL labs > Pappin lab
Depositing User: Jessica Koos
Date Deposited: 15 Aug 2014 16:44
Last Modified: 15 Aug 2014 16:44
URI: http://repository.cshl.edu/id/eprint/30567

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