| First Author | Zhao B | Year | 2019 |
| Journal | Nat Immunol | Volume | 20 |
| Issue | 10 | Pages | 1381-1392 |
| PubMed ID | 31451788 | Mgi Jnum | J:280728 |
| Mgi Id | MGI:6369516 | Doi | 10.1038/s41590-019-0469-z |
| Citation | Zhao B, et al. (2019) Notch and the pre-TCR coordinate thymocyte proliferation by induction of the SCF subunits Fbxl1 and Fbxl12. Nat Immunol 20(10):1381-1392 |
| abstractText | Proliferation is tightly regulated during T cell development, and is limited to immature CD4(-)CD8(-) thymocytes. The major proliferative event is initiated at the 'beta-selection' stage following successful rearrangement of Tcrbeta, and is triggered by and dependent on concurrent signaling by Notch and the pre-T cell receptor (TCR); however, it is unclear how these signals cooperate to promote cell proliferation. Here, we found that beta-selection-associated proliferation required the combined activity of two Skp-cullin-F-box (SCF) ubiquitin ligase complexes that included as substrate recognition subunits the F-box proteins Fbxl1 or Fbxl12. Both SCF complexes targeted the cyclin-dependent kinase inhibitor Cdkn1b for polyubiquitination and proteasomal degradation. We found that Notch signals induced the transcription of Fbxl1, whereas pre-TCR signals induced the transcription of Fbxl12. Thus, concurrent Notch and pre-TCR signaling induced the expression of two genes, Fbxl1 and Fbxl12, whose products functioned identically but additively to promote degradation of Cdkn1b, cell cycle progression, and proliferation of beta-selected thymocytes. |
