A novel mechanism for GABA synthesis and packaging into synaptic vesicles
Chandana Buddhala1, Che-Chang Hsu, Jang-Yen Wu
1Department of Basic Science, Florida Atlantic University, Boca Raton, FL 33431, United States.
Neurochemistry International
|May 12, 2009
Summary
This review explores how l-glutamic acid decarboxylase (GAD) is regulated, focusing on its role in synthesizing the inhibitory neurotransmitter gamma-amino butyric acid (GABA). New findings suggest mitochondrial GAD65 may fuel GABA production and packaging.
Area of Science:
- Neuroscience
- Biochemistry
- Molecular Biology
Background:
- Gamma-amino butyric acid (GABA) is the primary inhibitory neurotransmitter in the brain.
- Dysfunctional GABA neurotransmission is linked to neurodegenerative diseases.
- L-glutamic acid decarboxylase (GAD) synthesizes GABA, making its regulation critical.
Purpose of the Study:
- To review recent advances in understanding the regulation of GAD.
- To present new evidence on the localization and function of GAD65.
- To propose a model for mitochondrial GAD65's role in GABA synthesis and packaging.
Main Methods:
- Literature review of GAD regulation mechanisms.
- Analysis of new evidence regarding GAD65 localization.
- Development of a functional model for mitochondrial GAD65.
Main Results:
- GAD is regulated transcriptionally (alternative splicing) and post-translationally (phosphorylation, palmitoylation, cleavage).
- Evidence indicates GAD65 is present in mitochondria within axon terminals.
- A model is proposed where mitochondrial GAD65 generates ATP to support GABA synthesis and vesicular transport.
Conclusions:
- Understanding GAD regulation is crucial for addressing GABAergic deficits in neurodegeneration.
- Mitochondrial GAD65 plays a potential key role in energy supply for GABAergic neurotransmission.
- Further research into mitochondrial GAD65 function could reveal new therapeutic targets.
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