Molecular cloning and characterization of the ABC transporter expressed in trachea (ATET) gene from Drosophila melanogaster

A novel member of the ATP-binding cassette (ABC) transporter proteins has been cloned from Drosophila melanogaster. The gene is designated as ABC Transporter Expressed in Trachea (Atet), because the transcript was localized to the respiratory system by in situ hybridization analysis of whole-mount embryos using digoxigenin-labeled RNA probes. The hybridization signal was also observed in amnioserosa. Northern blot analysis identified a single 4.5 kb mRNA expressed in all developmental stages at a relatively constant lever. The Atet gene mapped to 24E on the left arm of the second chromosome. The Atet protein shows extensive homology with the Drosophila white gene product, which is reported to form heterodimers with the brown or scarlet gene product to transport guanine or tryptophan into the pigment cells in the compound eye. By analogy, Atet is suggested to be involved in transporting a small molecule after dimerization with a partner protein.