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Regulation of large dense-core vesicle volume and neurotransmitter content mediated by adaptor protein 3.

ABSTRACT: Adaptor protein 3 (AP-3) is a vesicle-coat protein that forms a heterotetrameric complex. Two types of AP-3 subunits are found in mammalian cells. Ubiquitous AP-3 subunits are expressed in all tissues of the body, including the brain. In addition, there are neuronal AP-3 subunits that are thought to serve neuron-specific functions such as neurotransmitter release. In this study, we show that overexpression of neuronal AP-3 in mouse chromaffin cells results in a striking decrease in the neurotransmitter content of individual vesicles (quantal size), whereas deletion of all AP-3 produces a dramatic increase in quantal size; these changes were correlated with alterations in dense-core vesicle size. AP-3 appears to localize in the trans-Golgi network and possibly immature secretory vesicles, where it may be involved in the formation of neurosecretory vesicles.

SUBMITTER: Grabner CP

PROVIDER: S-EPMC1502501 | biostudies-literature | 2006 Jun

REPOSITORIES: biostudies-literature

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Regulation of large dense-core vesicle volume and neurotransmitter content mediated by adaptor protein 3.

Grabner Chad P CP Price Steven D SD Lysakowski Anna A Cahill Anne L AL Fox Aaron P AP

Proceedings of the National Academy of Sciences of the United States of America 20060620 26

Adaptor protein 3 (AP-3) is a vesicle-coat protein that forms a heterotetrameric complex. Two types of AP-3 subunits are found in mammalian cells. Ubiquitous AP-3 subunits are expressed in all tissues of the body, including the brain. In addition, there are neuronal AP-3 subunits that are thought to serve neuron-specific functions such as neurotransmitter release. In this study, we show that overexpression of neuronal AP-3 in mouse chromaffin cells results in a striking decrease in the neurotran ...[more]

PMID: 16788073

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