Vesicular monoamine transporter

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Vesicular monoamine transporter
Properties of human protein
Mass / length primary structure 514 amino acids
Secondary to quaternary structure multipass membrane protein (11 TMS)
Identifier
Gene name SLC18A2
External IDs
Transporter classification
TCDB 2.A.1.2.29
designation Major Facilitator Super Family
Occurrence
Homology family SLC18
Parent taxon Vertebrates

The vesicular monoamine transporter (VMAT, VMAT2) is a protein in the membrane of cytoplasmic vesicles within nerve cells . It facilitates the influx of the neurotransmitters dopamine , serotonin , histamine and noradrenaline into the vesicles before they are emptied into the synaptic gap by means of exocytosis . VMAT2 is therefore a membrane transporter from the major facilitator superfamily . VMAT2 is only found in vertebrates . In humans, VMAT2 is localized in islet cells and in the uterus , in addition to the CNS . In the pancreas, VMAT2 plays a regulatory role in the insulin response to glucose .

The transport equation is:

Monoamine outside + H + inside ⇒ monoamine inside + H + outside

So it is an antiport .

There are gender differences in VMAT2 neuronal activity, which explains the different response to methamphetamine , as was found in a study with mice. The packaging of dopamine in dopaminergic neurons by VMAT2 is essential to prevent possible damage from oxidized dopamine in the event of oxidative stress or after methamphetamine intake. Mice with only 5-10% VMAT2 showed rapid damage to such neurons.

VMAT2 is a suitable target for the diagnosis of diabetes due to its close association with insulin production in islet cells .

Several substances are known to inhibit VMAT2, including reserpine and tetrabenazine .

In his book "The God Gene" (Eng. "The God Gene. Why Faith Is in Our Blood"), the molecular biologist Dean Hamer made VMAT2 responsible for people's religious feelings. The validity of his theory remains controversial.

Individual evidence

  1. ↑ UniProt Q05940
  2. ↑ BioGPS entry
  3. ↑ Raffo A, Hancock K, Polito T, et al : Role of vesicular monoamine transporter type 2 in rodent insulin secretion and glucose metabolism revealed by its specific antagonist tetrabenazine . In: J. Endocrinol. . 198, No. 1, July 2008, pp. 41-9. doi : 10.1677 / JOE-07-0632 . PMID 18577569 .
  4. ↑ Dluzen DE, McDermott JL: Sex differences in dopamine- and vesicular monoamine transporters functions . In: Ann. NY Acad. Sci. . 1139, October 2008, pp. 140-50. doi : 10.1196 / annals.1432.010 . PMID 18991858 .
  5. ↑ Guillot TS, Shepherd KR, Richardson JR, et al : Reduced vesicular storage of dopamine exacerbates methamphetamine-induced neurodegeneration and astrogliosis . In: J. Neurochem. . 106, No. 5, September 2008, pp. 2205-17. doi : 10.1111 / j.1471-4159.2008.05568.x . PMID 18643795 .
  6. ↑ Freeby M, Goland R, Ichise M, Maffei A, Leibel R, Harris P: VMAT2 quantitation by PET as a biomarker for beta-cell mass in health and disease . In: Diabetes Obes Metab . 10 Suppl 4, November 2008, pp. 98-108. doi : 10.1111 / j.1463-1326.2008.00943.x . PMID 18834437 .
  7. ↑ Saisho Y, Harris PE, Butler AE, et al : Relationship between pancreatic vesicular monoamine transporter 2 (VMAT2) and insulin expression in human pancreas . In: J. Mol. Histol. . 39, No. 5, October 2008, pp. 543-51. doi : 10.1007 / s10735-008-9195-9 . PMID 18791800 . PMC 2566800 (free full text).
  8. ^ A gene as a source of faith (FAZ.net, December 8, 2004) ; Retrieved September 12, 2010

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