|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 7 March 2006
doi: 10.1242/jcs.02846
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
1 Instituto de Investigaciones Biotecnológicas, IIB-INTECH, Universidad de San Martín, 1650 San Martín, Buenos Aires, Argentina
2 Department of Biological Sciences, University of Iowa, Iowa City, IA 52242, USA
* Author for correspondence (e-mail: carregui{at}iib.unsam.edu.ar)
Accepted 14 December 2005
Here, we define the mechanism through which protein tyrosine phosphatase 1B (PTP1B) is targeted to cell-matrix adhesion sites. Green fluorescent protein (GFP)-labeled PTP1B bearing the substrate-trapping mutation D181A was found in punctate structures in lamellae. The puncta co-localized with focal adhesion kinase (FAK) and Src, and defined the distal tips of cell-matrix adhesion sites identified with paxillin and vinculin. PTP1B is largely associated with the external face of the endoplasmic reticulum (ER) and the puncta develop from ER projections over cell-matrix adhesion sites, a process dependent on microtubules. Deletion of the ER-targeting sequence resulted in cytosolic localization and altered the distribution of PTP1B at cell-matrix foci, whereas mutations disrupting interactions with Src homology 3 (SH3) domains, and the insulin and cadherin receptors had no effect. PTP1B recognizes substrates within forming adhesion foci as revealed by its preferential association with paxillin as opposed to zyxin-containing foci. Our results suggest that PTP1B targets to immature cell-matrix foci in newly forming lamellae by dynamic extensions of the ER and contributes to the maturation of these sites.
Key words: PTP1B tyrosine phosphatase, Cell-matrix adhesion, Endoplasmic reticulum, Integrin signaling, Microtubules
Related articles in JCS:
This article has been cited by other articles:
![]() |
Y. Nakamura, N. Patrushev, H. Inomata, D. Mehta, N. Urao, H. W. Kim, M. Razvi, V. Kini, K. Mahadev, B. J. Goldstein, et al. Role of Protein Tyrosine Phosphatase 1B in Vascular Endothelial Growth Factor Signaling and Cell-Cell Adhesions in Endothelial Cells Circ. Res., May 23, 2008; 102(10): 1182 - 1191. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. L. Cortesio, K. T. Chan, B. J. Perrin, N. O. Burton, S. Zhang, Z.-Y. Zhang, and A. Huttenlocher Calpain 2 and PTP1B function in a novel pathway with Src to regulate invadopodia dynamics and breast cancer cell invasion J. Cell Biol., March 5, 2008; 180(5): 957 - 971. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Jaggi, M. A. Cabrita, A.-K. T. Perl, and G. Christofori Modulation of Endocrine Pancreas Development but not {beta}-Cell Carcinogenesis by Sprouty4 Mol. Cancer Res., March 1, 2008; 6(3): 468 - 482. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Ulianich, C. Garbi, A. S. Treglia, D. Punzi, C. Miele, G. A. Raciti, F. Beguinot, E. Consiglio, and B. Di Jeso ER stress is associated with dedifferentiation and an epithelial-to-mesenchymal transition-like phenotype in PC Cl3 thyroid cells J. Cell Sci., February 15, 2008; 121(4): 477 - 486. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.-H. Huang, T.-Y. Lin, R.-L. Pan, and J.-L. Juang The Involvement of Abl and PTP61F in the Regulation of Abi Protein Localization and Stability and Lamella Formation in Drosophila S2 Cells J. Biol. Chem., November 2, 2007; 282(44): 32442 - 32452. [Abstract] [Full Text] [PDF] |
||||