The vesicular acetylcholine transporter (VAChT) has been identified and characterized based on the acquisition of high
affinity vesamicol binding and proton-dependent, vesamicol-sensitive acetylcholine accumulation by a fibroblast cell
line transfected with a clone from a rat pheochromocytoma cDNA library encoding this protein Erickson JD et al 1994 . The distribution of
VAChT mRNA coincides with that reported for choline acetyltransferase (ChAT), the enzyme required for
acetylcholine biosynthesis, in the peripheral and central cholinergic nervous systems.
General function
Receptor, Channel/transport protein
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Cellular localization
Plasma membrane
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Ovarian function
Follicle development, Antral follicle growth
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Expression regulated by
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Ovarian localization
Granulosa, Luteal cells
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Fritz S, et al reported the evidence for expression of
choline-acetyltransferase and vesicular acetylcholine transporter
in human granulosa-luteal cells.
The authors demonstrated the ability of muscarinic agonists to stimulate the proliferation of
human GC within 24 h. In vivo, ACh, the natural ligand of these receptors is
thought to be contained in cholinergic nerve fibers innervating the ovary.
Surprisingly, the prerequisite for the synthesis of ACh, the enzyme
choline-acetyltransferase (ChAT), is also expressed by human GC, as shown by Western blotting and immunocytochemistry. In addition, these cells express
another marker for ACh synthesis, namely the gene for the vesicular acetylcholine
transporter, as evidenced by RT-PCR cloning, Western blotting, and
immunocytochemistry. The data identify the M1 receptor in human
GC and point to a novel, trophic role of the neurotransmitter ACh. Furthermore,
the presence of the prerequisites of ACh synthesis in human GC indicate that an
autocrine/paracrine regulatory loop also exists in the in vivo counterparts of these
cells in the ovary, i.e. in the cells of the preovulatory follicle and/or of the young
corpus luteum.