Emerging roles for the FBXW7 ubiquitin ligase in leukemia and beyond.

Protein degradation plays key roles in diverse pathways in cell division, growth and differentiation. Aberrant stabilization of crucial proteins participating in oncogenic pathways is often observed in cancer. The importance of proper protein turnover is exemplified by the SCF(Fbxw7) ubiquitin ligase, which is frequently mutated in human cancer, including T cell acute lymphoblastic leukemia. Recent studies have revealed novel substrates of Fbxw7 and shed light on its role on differentiation of stem cells and expansion of stem-cell-like cells driving tumorigenesis. Detailed understanding of the contribution of the Fbxw7-regulated network of proteins in initiation and progression of cancer will facilitate the identification of candidate intervention targets in human cancer.