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Cited by 36Cell Adhesion Molecules ResearchBone and Dental Protein StudiesCellular Mechanics and Interactions

Identification of CD9 extracellular domains important in regulation of CHO cell adhesion to fibronectin and fibronectin pericellular matrix assembly

Cook, George A., Longhurst, Celia M., Grgurevich, Svetozar, Cholera, Shila, Crossno, Joseph T., Jennings, Lisa K.·2002·Blood
DOI 10.1182/blood.v100.13.4502
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Abstract

CD9, a 24-kDa member of the tetraspanin family, influences cellular growth and development, activation, adhesion, and motility. Our investigation focuses on the hypothesis that the CD9 second extracellular loop (EC2) is important in modulating cell adhesive events. Using a Chinese hamster ovary (CHO) cell expression system, we previously reported that CD9 expression inhibited cell adhesion to fibronectin and fibronectin matrix assembly. For the first time, a functional epitope on CD9 EC2 that regulates these processes is described. Binding of mAb7, an EC2-specific anti-CD9 monoclonal antibody, reversed the CD9 inhibitory activity on CHO cell adhesion and fibronectin matrix assembly. This reversal of cell phenotype also was observed in CHO cells expressing CD9 EC2 truncations. Furthermore, our data showed that the EC2 sequence173LETFTVKSCPDAIKEVFDNK192 was largely responsible for the CD9-mediated CHO cell phenotype. Two peptides, 135K-V172 (peptide 5b) and168P-I185 (peptide 6a), selectively blocked mAb7 binding to soluble CD9 and to CD9 on intact cells. These active peptides reversed the influence of CD9 expression on CHO cell adhesion to fibronectin. In addition, confocal microscopy revealed that CD9 colocalized with the integrin α5β1 and cytoskeletal F-actin in punctate clusters on the cell surface, particularly at the cell margins. Immunoprecipitation studies confirmed CD9 association with β1 integrin. The cellular distribution and colocalization of focal adhesion kinase and α-actinin with cytoskeletal actin was also influenced by CD9 expression. Thus, CD9 may exhibit its effect by modulating the composition of adhesive complexes important in facilitating cell adhesion and matrix assembly.

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Authors
Cook, G. A., Longhurst, C. M., Grgurevich, S., Cholera, S., Crossno, J. T., & Jennings, L. K.
Affiliations
University of Tennessee Health Science Center (US)
ORCID
Jennings, Lisa K.
Venue
Blood
Publisher
American Society of Hematology
Published
2002-12-15
Volume
100
Issue
13
Pages
4502-4511
ISSN
  • 0006-4971 (ISSN-L)
  • 1528-0020
DOI
10.1182/blood.v100.13.4502
OpenAlex
W2054753766
Cited by
36
References
45
Citations by year
2026: 1 · 2024: 3 · 2023: 2 · 2020: 2 · 2019: 1 · 2018: 1 · 2017: 1 · 2016: 1 · 2014: 4 · 2013: 3 · 2012: 1
FWCI
0.67
Type
journal article
Language
en
Open access
closed
Locations
  • Blood (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Institutes of Health (5r01hl053514-04)
  • National Heart, Lung, and Blood Institute (HL53514)
Topics
  • Health Sciences › Medicine › Immunology and Allergy › Cell Adhesion Molecules Research
  • Health Sciences › Medicine › Rheumatology › Bone and Dental Protein Studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Cellular Mechanics and Interactions
Keywords
CD9, tetraspanins, extracellular loop, cell adhesion, fibronectin, extracellular matrix assembly, alpha5beta1 integrin, focal adhesion kinase, alpha-actinin, F-actin, peptide mapping, CHO cells, cell adhesion inhibition
MeSH terms
Actins, Amino Acid Sequence, Animals, Antibodies, Monoclonal, Epitopes, Cell Adhesion, Cricetulus, Cytoskeleton, Extracellular Matrix, Fibronectins, Cricetinae, Humans, Membrane Glycoproteins, Membrane Proteins, Microscopy, Fluorescence, Models, Molecular, Molecular Sequence Data, Peptide Fragments, Protein Conformation, Protein-Tyrosine Kinases, Recombinant Fusion Proteins, Transfection, Antigens, CD, CHO Cells, Sequence Deletion, Protein Structure, Tertiary, Microscopy, Confocal, Protein Interaction Mapping, Integrin alpha5beta1, Macromolecular Substances, Focal Adhesion Protein-Tyrosine Kinases, Focal Adhesion Kinase 1, Tetraspanin 29

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