| First Author | Hernández MV | Year | 2006 |
| Journal | J Cell Sci | Volume | 119 |
| Issue | Pt 7 | Pages | 1233-43 |
| PubMed ID | 16522684 | Mgi Jnum | J:106995 |
| Mgi Id | MGI:3619857 | Doi | 10.1242/jcs.02846 |
| Citation | Hernandez MV, et al. (2006) ER-bound PTP1B is targeted to newly forming cell-matrix adhesions. J Cell Sci 119(Pt 7):1233-43 |
| abstractText | 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. |
