Signaling via Shc family adapter proteins

Area of Science:

• Cellular and Molecular Biology
• Signal Transduction
• Oncogenesis

Background:

• The adapter protein Shc, initially identified as an SH2-containing proto-oncogene, plays a role in growth factor signaling.
• Shc proteins are implicated in signaling pathways of diverse receptors, including growth factor, antigen, cytokine, G-protein coupled, hormone receptors, and integrins.
• Ubiquitous ShcA and neuronally expressed ShcB/ShcC isoforms have been identified, with ShcA knockout mice proving embryonic lethal.

Purpose of the Study:

• To elucidate the multifaceted roles of Shc adapter proteins in cellular signaling.
• To investigate the mechanistic underpinnings of Shc-mediated signaling beyond mitogen-activated protein kinase (MAPK) activation.
• To understand the critical role of Shc in receptor-mediated cellular responses.

Main Methods:

• Analysis of ShcA knockout mouse models.
• Dominant-negative studies to probe Shc function.
• Investigation of Shc involvement in various receptor signaling pathways.

Main Results:

• A critical role for Shc in mitogen-activated protein kinase (MAPK) activation is established.
• Shc signaling is implicated in diverse cellular processes, including c-Myc activation and cell survival.
• ShcA knockout mice exhibit embryonic lethality, highlighting ShcA's in vivo importance.

Conclusions:

• Shc proteins are central mediators in signaling pathways activated by a wide array of receptors.
• While Shc's role in MAPK activation is clear, its involvement in other signaling events requires further mechanistic characterization.
• Understanding Shc-mediated signaling is essential for comprehending the biological effects governed by numerous receptor systems.