A Smad action turnover switch operated by WW domain readers of a phosphoserine code

SMURF and NEDD4: sharp shooters monitor the gate keepers and ion traffic controllers of lead astray cell

It is becoming increasingly apparent that a complex bar code underlies the quantitative aspects of extracellular signal regulation. Cell type-specific and context-dependent transcriptional programs are triggered by sophisticated nanomachinery consisting of HECT enzymes which monitor signal generation, transduction and termination. How the HECT enzymes safeguard spatiotemporal organization was a fundamental question towards understanding the process of protein degradation and its functions in diverse biological processes. In this review we will dismantle how HECT E3 enzymes regulate the trafficking of many receptors, channels and transporters as well as how HECT enzymes negatively regulate each other. There is accumulating evidence that suggests an undeniable role of HECT enzymes in regulating mediators of the Wnt signal-transduction cascade. By contrast, little is known about the crosstalk of HECT enzymes with ATM and TRAIL in prostate cancer, but several hints have emerged. This review provides a broader snapshot for studying multiple pathways in parallel, rather than as separate entities.

Integrating developmental signals: a Hippo in the (path)way

The Hippo pathway, a signaling cascade that controls cell cycle progression, apoptosis and cell differentiation, has emerged as a fundamental regulator of many physiological and pathological processes. Recent studies have revealed a complex network of interactions directing Hippo pathway activity, and have connected this pathway with other key signaling pathways. Such crosstalk has uncovered novel roles for Hippo signaling, including regulation of TGFβ/SMAD and WNT/β-catenin pathways. This review highlights some of the recent findings in the Hippo field with an emphasis on how the Hippo pathway is integrated with other pathways to mediate diverse processes.