| First Author | Karlsson S | Year | 2006 |
| Journal | Mol Biol Cell | Volume | 17 |
| Issue | 11 | Pages | 4846-55 |
| PubMed ID | 16971512 | Mgi Jnum | J:117940 |
| Mgi Id | MGI:3698080 | Doi | 10.1091/mbc.E06-04-0306 |
| Citation | Karlsson S, et al. (2006) Loss of T-cell protein tyrosine phosphatase induces recycling of the platelet-derived growth factor (PDGF) beta-receptor but not the PDGF alpha-receptor. Mol Biol Cell 17(11):4846-55 |
| abstractText | We have previously shown that the T-cell protein tyrosine phosphatase (TC-PTP) dephosphorylates the platelet-derived growth factor (PDGF) beta-receptor. Here, we show that the increased PDGF beta-receptor phosphorylation in TC-PTP knockout (ko) mouse embryonic fibroblasts (MEFs) occurs primarily on the cell surface. The increased phosphorylation is accompanied by a TC-PTP-dependent, monensin-sensitive delay in clearance of cell surface PDGF beta-receptors and delayed receptor degradation, suggesting PDGF beta-receptor recycling. Recycled receptors could also be directly detected on the cell surface of TC-PTP ko MEFs. The effect of TC-PTP depletion was specific for the PDGF beta-receptor, because PDGF alpha-receptor homodimers were cleared from the cell surface at the same rate in TC-PTP ko MEFs as in wild-type MEFs. Interestingly, PDGF alphabeta-receptor heterodimers were recycling. Analysis by confocal microscopy revealed that, in TC-PTP ko MEFs, activated PDGF beta-receptors colocalized with Rab4a, a marker for rapid recycling. In accordance with this, transient expression of a dominant-negative Rab4a construct increased the rate of clearance of cell surface receptors on TC-PTP ko MEFs. Thus, loss of TC-PTP specifically redirects the PDGF beta-receptor toward rapid recycling, which is the first evidence of differential trafficking of PDGF receptor family members. |
