Primary structure and functional expression of a Drosophila cyclic nucleotide-gated channel present in eyes and antennae.
Cyclic nucleotide-gated (CNG) ion channels serve as downstream targets of signalling pathways in vertebrate photoreceptors and olfactory sensory neurons. Whether CNG channels subserve similar functions in invertebrate photoreception and olfaction is unknown. We have cloned genomic DNA and cDNA encoding a cGMP-gated channel from Drosophila. The gene contains at least seven exons. Heterologous expression of cloned cDNA in both Xenopus oocytes and HEK 293 cells gives rise to functional ion channels. The Drosophila CNG channel is approximately 50-fold more sensitive to cGMP than to cAMP. The voltage dependence of blockage by divalent cations is different compared with the CNG channel of rod photoreceptors, and the Ca2+ permeability is much larger. The channel mRNA is expressed in antennae and the visual system of Drosophila. It is proposed that CNG channels are involved in transduction cascades of both invertebrate photoreceptors and olfactory sensillae.
Institut für Biologische Informationsverarbeitung, Forschungszentrum Jülich, Germany.
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Baumann
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Frings
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Godde
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Seifert
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Kaupp
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000096:biosynthesis / Q000235:genetics*; D002412:Cations / Q000378:metabolism; D003001:Cloning, Molecular; D006152:Cyclic GMP / Q000378:metabolism*; D054815:Cyclic Nucleotide-Gated Cation Channels; D018076:DNA, Complementary / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D004553:Electric Conductivity; D004594:Electrophysiology / Q000379:methods; D005091:Exons / Q000235:genetics; D017344:Genes, Insect / Q000235:genetics; D015698:Genomic Library; D006031:Glycosylation; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D009865:Oocytes; D012333:RNA, Messenger / Q000302:isolation & purification; D011984:Sensory Receptor Cells / Q000502:physiology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012903:Smell / Q000502:physiology; D014018:Tissue Distribution; D014785:Vision, Ocular / Q000502:physiology; D014981:Xenopus
D015220:Calcium Channels; D002412:Cations; C090451:CngA protein, Drosophila; D054815:Cyclic Nucleotide-Gated Cation Channels; D018076:DNA, Complementary; D029721:Drosophila Proteins; D012333:RNA, Messenger; D006152:Cyclic GMP; D002118:Calcium