Homer1c interacts with Hippi and protects striatal neurons from apoptosis

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Death Research

Background:

• Postsynaptic scaffold protein Homer1c plays a role in neuronal function.
• Homer protein interacting protein 1 (Hippi) is a cell death-promoting protein implicated in striatal neurodegeneration.
• Huntington's disease is a neurodegenerative disorder primarily affecting the striatum.

Purpose of the Study:

• To investigate the interaction between Homer1c and Hippi.
• To determine the role of Homer1c in Hippi-induced neuronal apoptosis.
• To elucidate the specific neuronal populations affected by Hippi-mediated cell death.

Main Methods:

• Yeast two-hybrid screening of a mouse brain cDNA library.
• Co-expression studies in cultured striatal and hippocampal neurons.
• Analysis of Hippi binding domain deletions.

Main Results:

• Hippi specifically binds to Homer1c, not Homer2.
• Hippi induces apoptosis selectively in striatal neurons, not hippocampal neurons.
• Co-expression of Homer1c prevents Hippi-induced striatal neuron death, dependent on the Hippi binding domain.

Conclusions:

• Homer1c acts as a specific binding partner for Hippi.
• Homer1c exhibits a neuroprotective effect against Hippi-induced apoptosis in the striatum.
• These findings highlight Homer1c's critical role in regulating neuronal death mechanisms within the striatum.