Functional characterization of a de novo missense variant in the SLC6A3 gene originally identified in a simplex ASD case as part of a whole-exome sequencing study in 175 ASD parent-child trios (originally described by Neale et al. in a 2012 Nature report) showed that this variant (T356M) resulted in anomalous dopamine transporter function and hyperactivity when expressed in the DA neurons of Drosophila (Hamilton et al., 2013). A missense variant in this same gene (p.Ala559Val), previously identified in individuals with ADHD (Mazei-Robison et al., 2005) and bipolar disorder (Grunhage et al., 2000), was recently identified in two unrelated male ASD probands and shown to alter dopamine function and trafficking (Bowton et al., 2014).
Molecular Function
This gene encodes an amine transporter that terminates the action of dopamine by its high affinity sodium-dependent reuptake into presynaptic terminals. Mutations in this gene are associated with Parkinsonism-dystonia infantile (PKDYS) [MIM:613135], while variation in the number of 40 bp tandem repeats in the 3'UTR of this gene is associated with idiopathic epilepsy, attention-deficit hyperactivity disorder, dependence on alcohol and cocaine, susceptibility to Parkinson disease and protection against nicotine dependence.
External Links
References
Type
Title
Type of Disorder
Associated Disorders
Author, Year
Primary
De novo mutation in the dopamine transporter gene associates dopamine dysfunction with autism spectrum disorder.
The dopamine transporter, Slc6a3 is knocked out in the model and homozygotes for targeted null mutations exhibit hyperactivity and impaired spatial cognitive function.
References
Type
Title
Author, Year
Additional
Impaired spatial working memory and decreased frontal cortex BDNF protein level in dopamine transporter knockout mice.
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
The DAT or Slc6a3 gene was inactivated by replacement of exon I and exon II with a neomycin resistance cassette.
Allele Type: Targeted (Knock-out)
Strain of Origin: 129SvEv
Genetic Background: C57BL/6*129Sv/J
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
The gene was disrupted by insertion of a neomycin resistance cassette into a coding exon via homologous recombination.
Allele Type: Targeted (Knock-out)
Strain of Origin: 129P2/OlaHsd
Genetic Background: C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
The alanine at position 559 of the Slc6a3 gene was mutated to Valine and this knock-in construct was used to electroporating ES cells resulting in a Val559 allele being knocked in following homologous recombination, detected by the presence of a neomycin resistance.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
The alanine at position 559 of the Slc6a3 gene was mutated to Valine and this knock-in construct was used to electroporating ES cells resulting in a Val559 allele being knocked in following homologous recombination, detected by the presence of a neomycin resistance.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Pharmaceutical intervention
Model Genotype:
Homozygous
Mutation:
Slc6a3-Val559 knocked in homozygous, freely moving mice were infused with 0.1uM AMPH intra-striatally using microdialysis and cannulae.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Pharmaceutical intervention
Model Genotype:
Homozygous
Mutation:
Slc6a3-Val559 knocked in homozygous mice were injected with 3mg/kg of AMPH (i.p.). This amount of drug an intermediate dose for locomotor activation in wild type mice.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Pharmaceutical intervention
Model Genotype:
Homozygous
Mutation:
Slc6a3-Val559 knocked in homozygous mice were injected with 10mg/kg of MPH (i.p.). This amount of drug an intermediate dose for locomotor activation in wild type mice.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Pharmaceutical intervention
Model Genotype:
Heterozygous
Mutation:
Slc6a3-Val559 knocked in heterozygous , freely moving mice were infused with 0.1uM AMPH intra-striatally using microdialysis and cannulae.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Pharmaceutical intervention
Model Genotype:
Heterozygous
Mutation:
Slc6a3-Val559 knocked in heterozygous mice were injected with 3mg/kg of AMPH (i.p.). This amount of drug an intermediate dose for locomotor activation in wild type mice.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Pharmaceutical intervention
Model Genotype:
Heterozygous
Mutation:
Slc6a3-Val559 knocked in heterozygous mice were injected with 10mg/kg of MPH (i.p.). This amount of drug an intermediate dose for locomotor activation in wild type mice.
Allele Type: Targeted (Knock-in)
Strain of Origin: Genetic Background: 129S6/SvEvTac*C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
Mice bearing an ASD-associated de novo mutation in the SLC6A3 gene resulting in a threonine to methionine substitution at site 355 in exon 8, expressed under the control of the endogenous Slc6a3 promoter. The mouse ortholog of the human T356M variant is T355M.
Allele Type: LOF Knock-in
Strain of Origin: Genetic Background: C57BL/6
ES Cell Line: Mutant ES Cell Line: Model Source: genOway S.A. (Lyon, France)
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
The DAT or Slc6a3 gene was inactivated by replacement of exon I and exon II with a neomycin resistance cassette. The positive ES cell lines were injected into the blastocyst of CD1 pseudopregnant mice to generate chimeras. Then the chimeras were mated to C57BL/6 to get F1. Which were mated together for the studies.
Allele Type: Targeted (Knock-out)
Strain of Origin: 129SvEv
Genetic Background: C57BL/6*CD1
ES Cell Line: Mutant ES Cell Line: Model Source:
Description: Spontaneous alternation was decreased in the slc6a3 (dat) ko mice, compared to controls. no difference in total number of arm entries was seen between the the ko and the control groups.
Exp Paradigm: Total number of entries in the 2 arms of the y maze and alternation behavior were recorded
Description: The amount of brain derived neurotrophic factor (bdnf) protein is reduced in the cortex of the slc6a3 nullizugous mice, to about 50% of the controls.
Exp Paradigm: Gene regulation
Description: Increased locomotor activity measured as the distance traveled and increased rearing measured as vertical activities
Exp Paradigm: Locomotor activity is measured as the distance traveled and rearing is measured as vertical activities
Description: Decreased sensorimotor gating measured by increased startle responses and decreased in ppi
Exp Paradigm: Prepulse trials consisted of a 20 ms pre-pulse stimulus that was 4,8, or 12 db above white noise background. followed 100 ms later by the 120 db startle stimulus
Description: Decreased social learning is measured by no preference for familiar diet without reduction in total food comsumed
Exp Paradigm: Mice were tested for short and long term memory ( 3 days) and remote social memory after interaction with the demonstrator mouse
Description: Decreased object recognition measured by no preference to novel objects without reduced interaction in object exploration
Exp Paradigm: Short and long term memory was tested, 20 min (stm) and 24 hrs (ltm) or 14 days (remote)
Description: There is a reduction in amount of time and no. or rearings observed in val559 knock in homozygous mice compared to wild type
Exp Paradigm: NA
Decay kinetics of miniature post synaptic currents2
Increased
Description: The d2r mediated ipscs are prolonged in the substantia nigra dopamine neurons with a longer time to peak and duration. they are also prolonged in the midbrain, where dopamine is spontaneously released
Exp Paradigm: NA
Description: There is a small but significant increase in serotonin levels in the striatum and cortex in the val559 homozygous mice (not hets) compared to wild type mice
Exp Paradigm: NA
Description: The number of homozygous males obtained from normal breeding was reduced with a significant deviation from hardy-weinberg distribution. genotype distribution in females was normal
Exp Paradigm: NA
Description: There is a reduction in amount of time and no. or rearings observed in val559 knock in heterozygous mice compared to wild type
Exp Paradigm: NA
Description: Slc6a3 val559 mice with striatally infused amph had a dampened increase da levels compared to wild type, demonstrating the reduced ability of amph to cause da release in the knock ins
Exp Paradigm: NA
Description: Mph injected slc6a3 val559 knock in homozygous mice also show reduced no. and time spent in rearings, similar to amph injected knock ins
Exp Paradigm: NA
Description: Slc6a3 val559 mice with striatally infused amph had a dampened increase da levels compared to wild type, demonstrating the reduced ability of amph to cause da release in the knock ins
Exp Paradigm: NA
Description: Mph injected slc6a3 val559 knock in heterozygous mice also show reduced no. of rearings ( no difference was observable in the time spent, unlike homozygous mice) , similar to amph injected knock ins
Exp Paradigm: NA
Description: Mutants show impaired striatal da reuptake compared with controls. the decrease in peak current in the presence of cocaine confirms the identity of the dopaminergic currents.
Exp Paradigm: Carbon fiber amperometry; dat is a target for cocaine; striatum
Decay kinetics of miniature post synaptic currents1
Increased
Description: Mutants show increase in decay time of striatal dopaminergic signals compared with controls. in the presence of cocaine, decay time of both wildtype and mutant striatal dopaminergic signals were increased, confirming the identity of dopaminergic currents.
Exp Paradigm: Striatum; dat is a target for cocaine
Description: Mutants show decreased activation of erk1/2 but not erk2 compared with controls as measured by the phosphorylation of erk1/2 and erk2.
Exp Paradigm: Striatum
Description: Mutants show decreased levels of activated tyrosine hydroxylase compared with controls.
Exp Paradigm: Striatum; dat is a target for cocaine; activity of th is partially regulated by phosphorylation of the residue ser31
