Functions Of APC/C-CDH1 In Postmitotic Neurons

The Anaphase Promoting Complex/Cyclosome-Cdh1 (APC/C-Cdh1) is a multiprotein complex known for its role in cell cycle regulation, specifically in targeting cell cycle proteins for degradation during mitosis. However, recent studies have revealed novel functions of APC/C-Cdh1 in postmitotic neurons. Here are some key points regarding the functions of APC/C-Cdh1 in postmitotic neurons:

1. Neuronal Survival:

o Cyclin B1 Degradation: In postmitotic neurons, APC/C-Cdh1 promotes the continuous degradation of cyclin B1, a key cell cycle regulator. By targeting cyclin B1 for proteasomal degradation, APC/C-Cdh1 prevents its nuclear accumulation and inhibits cell cycle re-entry, thereby promoting neuronal survival.

o Apoptosis Regulation: Dysregulation of APC/C-Cdh1-mediated cyclin B1 degradation in postmitotic neurons can lead to aberrant cell cycle activation and apoptosis. Maintaining proper APC/C-Cdh1 activity is crucial for preventing neuronal cell death and ensuring long-term neuronal survival.

2. Axonal Growth and Synaptogenesis:

o Regulation of Developmental Processes: APC/C-Cdh1 has been implicated in regulating axonal growth and synaptogenesis in postmitotic neurons. By controlling the degradation of specific proteins involved in neuronal development, APC/C-Cdh1 influences the structural and functional maturation of neurons.

o Synaptic Connectivity: Proper functioning of APC/C-Cdh1 is essential for establishing and maintaining synaptic connectivity in the brain. Disruption of APC/C-Cdh1 activity can impact synaptic plasticity and neuronal network formation, potentially leading to cognitive deficits.

3. Glucidic Metabolism:

o Metabolic Regulation: APC/C-Cdh1 has been linked to the regulation of glucidic (carbohydrate) metabolism in postmitotic neurons. By modulating the stability of metabolic enzymes or regulators, APC/C-Cdh1 may influence energy production and utilization in neurons, thereby impacting neuronal function and viability.

o Metabolic Homeostasis: Maintaining metabolic homeostasis is crucial for neuronal health and function. APC/C-Cdh1-mediated control of glucidic metabolism pathways in postmitotic neurons highlights the diverse roles of this complex beyond cell cycle regulation.

4. In Vivo Studies:

o Mouse Models: Studies using specific neuronal knockout mouse models for Cdh1 have demonstrated the importance of APC/C-Cdh1 in neuronal survival in vivo. Depletion of Cdh1 in the brain leads to selective neuronal loss, emphasizing the essential role of APC/C-Cdh1 in maintaining neuronal integrity and function.

o Layer-Specific Effects: Cdh1 depletion in the cerebral cortex results in a time-dependent shortening of specific cortical layers, indicating a progressive loss of neurons. These in vivo findings underscore the significance of APC/C-Cdh1 in preserving neuronal populations and cortical architecture.

In conclusion, APC/C-Cdh1 plays critical roles in postmitotic neurons beyond its canonical function in cell cycle regulation. By influencing neuronal survival, axonal growth, synaptogenesis, and metabolic processes, APC/C-Cdh1 contributes to the maintenance of neuronal integrity and function. Understanding the diverse functions of APC/C-Cdh1 in postmitotic neurons provides insights into the molecular mechanisms underlying neuronal development, connectivity, and metabolic homeostasis, with implications for neurodegenerative disorders and cognitive function.

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Mashtishk Vigyan Anusandhan

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