|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 6 January 2004
doi: 10.1242/jcs.00879
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
1 School of Molecular and Microbial Sciences, Institute for Molecular Bioscience and CRC for Chronic Inflammatory Diseases, University of Queensland, Brisbane, QLD 4072, Australia
2 Yamanouchi Research Institute, Littlemore Park, Armstrong Road, Oxford OX4 4XS, UK
3 Randall Centre, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
4 OSI Pharmaceuticals, Watlington Road, Oxford, OX4 6LT, UK
5 Oxford Glycosciences plc, The Forum, 86 Milton Park, Abingdon, Oxon OX14, UK
* Author for correspondence (e-mail: s.kellie{at}mailbox.uq.edu.au)
Accepted 12 September 2003
The receptor protein tyrosine phosphatase density-enhanced phosphatase-1 (DEP-1) has been implicated in aberrant cancer cell growth and immune cell function, however, its function within cells has yet to be properly elucidated. To investigate the cellular function of DEP-1, stable cell lines inducibly expressing DEP-1 were generated. Induction of DEP-1 expression was found to decrease PDGF-stimulated tyrosine phosphorylation of a number of cellular proteins including the PDGF receptor, and to inhibit growth factor-stimulated phosphorylation of components of the MAPK pathway, indicating that DEP-1 antagonised PDGF receptor signalling. This was supported by data showing that DEP-1 expression resulted in a reduction in cell proliferation. DEP-1-expressing cells had fewer actin-containing microfilament bundles, reduced vinculin and paxillin-containing adhesion plaques, and were defective in interactions with fibronectin. Defective cell-substratum adhesion correlated with lack of activation of FAK in DEP-1-expressing cells. Time-lapse interference reflection microscopy of live cells revealed that although small focal contacts at the leading edge were generated in DEP-1-expressing cells, they failed to mature into stable focal adhesions, as found in control cells. Further motility analysis revealed that DEP-1-expressing cells retained limited random motility, but showed no chemotaxis towards a gradient of PDGF. In addition, cell-cell contacts were disrupted, with a change in the localisation of cadherin from discrete areas of cell-cell contact to large areas of membrane interaction, and there was a parallel redistribution of ß-catenin. These results demonstrate that DEP-1 is a negative regulator of cell proliferation, cell-substratum contacts, motility and chemotaxis in fibroblasts.
Key words: Tyrosine phosphatase, Cytoskeleton, Motility
Related articles in JCS:
This article has been cited by other articles:
![]() |
F. Barbieri, A. Pattarozzi, M. Gatti, C. Porcile, A. Bajetto, A. Ferrari, M. D. Culler, and T. Florio Somatostatin Receptors 1, 2, and 5 Cooperate in the Somatostatin Inhibition of C6 Glioma Cell Proliferation in Vitro via a Phosphotyrosine Phosphatase-{eta}-Dependent Inhibition of Extracellularly Regulated Kinase-1/2 Endocrinology, September 1, 2008; 149(9): 4736 - 4746. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kimura, K. Kawamoto, S. Teranishi, and T. Nishida Role of rac1 in fibronectin-induced adhesion and motility of human corneal epithelial cells. Invest. Ophthalmol. Vis. Sci., October 1, 2006; 47(10): 4323 - 4329. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Takahashi, K. Takahashi, R. L. Mernaugh, N. Tsuboi, H. Liu, and T. O. Daniel A monoclonal antibody against CD148, a receptor-like tyrosine phosphatase, inhibits endothelial-cell growth and angiogenesis Blood, August 15, 2006; 108(4): 1234 - 1242. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Sallee, E. S. Wittchen, and K. Burridge Regulation of Cell Adhesion by Protein-tyrosine Phosphatases: II. CELL-CELL ADHESION J. Biol. Chem., June 16, 2006; 281(24): 16189 - 16192. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Iervolino, R. Iuliano, F. Trapasso, G. Viglietto, R. M. Melillo, F. Carlomagno, M. Santoro, and A. Fusco The Receptor-Type Protein Tyrosine Phosphatase J Antagonizes the Biochemical and Biological Effects of RET-Derived Oncoproteins. Cancer Res., June 15, 2006; 66(12): 6280 - 6287. [Abstract] [Full Text] [PDF] |
||||