Mdm2 induces mono-ubiquitination of FOXO4.

Background: The Forkhead box O (FOXO) class of transcription factors are involved in the regulation of several cellular responses including cell cycle progression and apoptosis. Furthermore, in model organisms FOXOs act as tumor suppressors and affect aging. Previously, we noted that FOXOs and p53 are remarkably similar within their spectrum of regulatory proteins.

Interaction of FOXO with beta-catenin inhibits beta-catenin/T cell factor activity.

Wingless (Wnt) signaling regulates many aspects of development and tissue homeostasis, and aberrant Wnt signaling can lead to cancer. Upon a Wnt signal beta-catenin degradation is halted and consequently the level of beta-catenin in the cytoplasm increases. This allows entry of beta-catenin into the nucleus where it can regulate gene transcription by direct binding to members of the lymphoid enhancer factor/T cell factor (TCF) family of transcription factors.

The X factor: skewing X inactivation towards cancer.

Increased expression of the epidermal growth factor receptor HER-2/ErbB2 is frequently observed in breast cancer and is targeted by the anticancer drug Herceptin. Now, Zuo et al. (2007) reveal that an X-linked gene encoding the transcription factor FOXP3 is a breast cancer tumor suppressor that represses expression of HER2/ErbB2.

Characterization of testis-specific serine-threonine kinase 3 and its activation by phosphoinositide-dependent kinase-1-dependent signalling.

The family of testis-specific serine-threonine kinases (TSSKs) consists of four members whose expression is confined almost exclusively to testis. Very little is known about their physiological role and mechanisms of action. We cloned human and mouse TSSK3 and analysed the biochemical properties, substrate specificity and in vitro activation.