Hippo-Yap/Taz signaling: Complex network interactions and impact in epithelial cell behavior

Area of Science:

• Cellular Biology
• Molecular Biology
• Developmental Biology

Background:

• The Hippo pathway is a critical signaling network regulating organ size, development, and disease.
• While studied in model organisms, its precise function in mammalian systems requires further elucidation.
• Key pathway components regulate the transcriptional co-activators Yap and Taz, influencing cell proliferation and stemness.

Purpose of the Study:

• To review the regulatory mechanisms governing Yap/Taz nucleocytoplasmic shuttling.
• To explore the implications of these mechanisms for epithelial cell behavior.
• To highlight the lung as a model system for studying Hippo pathway functions.

Main Methods:

• Literature review of studies on the Hippo pathway, Yap/Taz proteins, and epithelial cell biology.
• Analysis of signaling inputs affecting the Hippo pathway, including growth factors and cell junctions.
• Focus on mechanisms controlling Yap/Taz localization and transcriptional activity.

Main Results:

• Yap/Taz localization is controlled by phosphorylation, determining their interaction partners and cellular functions.
• Nuclear Yap/Taz promote proliferation and stemness by interacting with TEAD transcription factors.
• Cytoplasmic Yap/Taz engage with other pathways or are degraded, influencing diverse cellular functions.

Conclusions:

• The Hippo pathway integrates diverse signals to control Yap/Taz localization and function.
• Nucleocytoplasmic shuttling of Yap/Taz is a central mechanism regulating epithelial cell behavior.
• Further research into the Hippo pathway's role in mammalian systems, particularly in organs like the lung, is crucial for understanding development and disease.