A genetic screen in Caenorhabditis elegans for dopamine neuron insensitivity to 6-hydroxydopamine identifies dopamine transporter mutants impacting transporter biosynthesis and trafficking

Richard Nass, Maureen K. Hahn, Tammy Jessen, Paul W. McDonald, Lucia Carvelli, Randy D. Blakely

Research output: Contribution to journalArticle

53 Scopus citations


The presynaptic dopamine (DA) transporter (DAT) is a major determinant of synaptic DA inactivation, an important target for psychostimulants including cocaine and amphetamine, and a mediator of DA neuron vulnerability to the neurotoxins 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpyridinium ion. To exploit genetic approaches for the study of DATs and neural degeneration, we exploited the visibility of green fluorescent protein (GFP)-tagged DA neurons in transgenic nematodes to implement a forward genetic screen for suppressors of 6-OHDA sensitivity. In our initial effort, we identified three novel dat-1 alleles conferring 6-OHDA resistance. Two of the dat-1 alleles derive from point mutations in conserved glycine residues (G55, G90) in contiguous DAT-1 transmembrane domains (TM1 and TM2, respectively), whereas the third allele results in altered translation of the transporter's COOH terminus. Our studies reveal biosynthetic, trafficking and functional defects in the DAT-1 mutants, exhibited both in vitro and in vivo. These studies validate a forward genetic approach to the isolation of DA neuron-specific toxin suppressors and point to critical contributions of the mutated residues, as well as elements of the DAT-1 COOH terminus, to functional expression of catecholamine transporters in neurons.

Original languageEnglish (US)
Pages (from-to)774-785
Number of pages12
JournalJournal of Neurochemistry
Issue number3
StatePublished - Aug 1 2005



  • 6-hydroxydopamine
  • Caenorhabditis elegans
  • Dopamine
  • Genetics
  • Nematode
  • Transport

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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