Abnormal chemosensory jump 6 is a positive transcriptional regulator of the cholinergic gene locus in Drosophila olfactory neurons.
Cholinergic neurons acquire their neurotransmitter phenotype, in part, by expressing the cholinergic gene locus. Previous studies have indicated that the 5' flanking DNA of the locus contains both positive and negative regulatory elements important for expression in different subsets of cholinergic neurons in Drosophila and other animals. Approximately 300 bases of proximal 5' flanking DNA control expression in Drosophila CNS neurons essential for viability, whereas more distal regulatory elements are important for expression in PNS sensory neurons. In this study we identify the POU domain transcription factor abnormal chemosensory jump 6 (Acj6) as a necessary positive transcriptional regulator for cholinergic locus expression in primary olfactory neurons. Choline acetyltransferase enzyme activity, protein levels, mRNA, and a fluorescent cholinergic reporter gene are all decreased in olfactory neurons of acj6 mutants. Decreased cholinergic expression was observed in both adults and larvae. The presence of a specific Acj6 binding site has been identified in the cholinergic locus 5' flanking DNA, suggesting that Acj6 may play a direct role in specifying the cholinergic neurotransmitter phenotype of most olfactory neurons. Transgenic expression of two different isoforms of Acj6 restricted to olfactory neurons indicates that additional trans factors may be required for cholinergic locus expression. Transgenic expression in all cholinergic neurons, however, results in lethality when a POU IV box element is absent but is essentially benign when present, indicating the importance of this motif in specifying different functional roles for Acj6.
Lee
Mi-Heon
MH
Division of Neuroscience, Beckman Research Institute of the City of Hope, Duarte, California 91010, USA.
Salvaterra
Paul M
PM
D024506:5' Flanking Region; D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites; D002460:Cell Line; D002795:Choline O-Acetyltransferase / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D017930:Genes, Reporter; D008297:Male; D008856:Microscopy, Fluorescence; D009154:Mutation; D009419:Nerve Tissue Proteins; D018034:Olfactory Receptor Neurons / Q000378:metabolism*; D050809:POU Domain Factors; D012333:RNA, Messenger / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D050809:POU Domain Factors; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; C068431:acj6 protein, Drosophila; D002795:Choline O-Acetyltransferase