Neuronal expression of the 5HT3 serotonin receptor gene requires nuclear factor 1 complexes.
The 5HT3 receptor (5HT3R) is a serotonin-gated ion channel whose expression is restricted to a subset of cells within the central and peripheral nervous systems. In vitro analysis shows that a small proximal region of the TATA-less 5HT3R promoter is sufficient to direct neuronal-specific reporter gene expression. Three potential regulatory elements conserved between the mouse and human genes were identified within this proximal promoter, two of which are known sites for the ubiquitously expressed factors Sp1 and nuclear factor 1 (NF1). Surprisingly, mutation of the NF1 binding site abolished all reporter activity in cell transfection studies, suggesting that this element is essential for neuronal-specific transcriptional activity of the 5HT3R. Furthermore, a complex of neuronal proteins that includes a member(s) of the NF1 family binds to this site, as shown by gel mobility super shift and DNaseI footprinting analyses. Although NF1 has been proposed to mediate basal transcription of many ubiquitously expressed genes, our data suggest that a member of the NF1 transcription factor family participates in neuronal-specific gene expression by promoting interactions with other regulatory factors found in sensory ganglia.
Department of Physiology, University of California at San Francisco, San Francisco, California 94143-0444, USA.
F K
FK
Bedford
D
D
Julius
H A
HA
Ingraham
D000818:Animals; D001483:Base Sequence; D022762:CCAAT-Enhancer-Binding Proteins; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics; D011985:Receptors, Serotonin / Q000235:genetics*; D016385:TATA Box / Q000235:genetics; D014157:Transcription Factors; D012668:Trigeminal Ganglion / Q000378:metabolism; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D051839:NFI Transcription Factors; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D011985:Receptors, Serotonin; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human