Presenilin-dependent ErbB4 nuclear signaling regulates the timing of astrogenesis in the developing brain

Area of Science:

• Neuroscience
• Cell Biology
• Molecular Biology

Background:

• Embryonic neural precursors differentiate into neurons or glial cells based on extracellular signals.
• Mechanisms integrating signals for timely neural precursor fate decisions were unclear.
• Receptor tyrosine kinases play roles in cell signaling and differentiation.

Purpose of the Study:

• To elucidate the mechanisms by which neural precursors integrate signals for fate determination.
• To investigate the role of receptor tyrosine kinase signaling in neural precursor fate choice.

Main Methods:

• Studied neuregulin-induced activation and presenilin-dependent cleavage of ErbB4.
• Analyzed the formation of a complex involving ErbB4's intracellular domain, TAB2, and N-CoR.
• Investigated nuclear translocation and binding to astrocytic gene promoters.
• Examined astrogenesis in ErbB4 knockout mice.

Main Results:

• ErbB4 activation leads to a nuclear complex that represses astrocytic gene expression.
• This signaling pathway maintains the neurogenic potential of precursors.
• ErbB4 knockout mice exhibit precocious astrogenesis, confirming ErbB4's inhibitory role.

Conclusions:

• Presenilin-dependent nuclear signaling by ErbB4 directly regulates gene transcription and cell fate in neural precursors.
• This pathway is crucial for timely neural development and may be relevant to Alzheimer's disease pathogenesis.