Display Settings:

Format

Send to:

Choose Destination
J Exp Med. 2007 Aug 6;204(8):1825-35. Epub 2007 Jul 23.

The SCFFBW7 ubiquitin ligase complex as a tumor suppressor in T cell leukemia.

Author information

  • 1Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.

Abstract

Recent studies have shown that activating mutations of NOTCH1 are responsible for the majority of T cell acute lymphoblastic leukemia (T-ALL) cases. Most of these mutations truncate its C-terminal domain, a region that is important for the NOTCH1 proteasome-mediated degradation. We report that the E3 ligase FBW7 targets NOTCH1 for ubiquitination and degradation. Our studies map in detail the amino acid degron sequence required for NOTCH1-FBW7 interaction. Furthermore, we identify inactivating FBW7 mutations in a large fraction of human T-ALL lines and primary leukemias. These mutations abrogate the binding of FBW7 not only to NOTCH1 but also to the two other characterized targets, c-Myc and cyclin E. The majority of the FBW7 mutations were present during relapse, and they were associated with NOTCH1 HD mutations. Interestingly, most of the T-ALL lines harboring FBW7 mutations were resistant to gamma-secretase inhibitor treatment and this resistance appeared to be related to the stabilization of the c-Myc protein. Our data suggest that FBW7 is a novel tumor suppressor in T cell leukemia, and implicate the loss of FBW7 function as a potential mechanism of drug resistance in T-ALL.

PMID:
17646408
[PubMed - indexed for MEDLINE]
PMCID:
PMC2118676
Free PMC Article

Images from this publication.See all images (5)Free text

Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk