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 a s ABC Transporter Expressed in Trachea (Atet), because the transcript was localized to the respiratory system by in situ hybridization analy sis of whole-mount embryos using digoxigenin-labeled RNA probes. The h ybridization signal was also observed in amnioserosa. Northern blot an alysis identified a single 4.5 kb mRNA expressed in all developmental stages at a relatively constant level. The Atet gene mapped to 24E on the left arm of the second chromosome. The Atet protein shows extensiv e homology with the Drosophila white gene product, which is reported t o form heterodimers with the brown or scarlet gene product to transpor t guanine or tryptophan into the pigment cells in the compound eye. By analogy, Atet is suggested to be involved in transporting a small mol ecule after dimerization with a partner protein.