Hashimoto C, Hudson K L, Anderson K V
Department of Molecular Biology, University of California, Berkeley 94720.
Cell. 1988 Jan 29;52(2):269-79. doi: 10.1016/0092-8674(88)90516-8.
The Toll gene of Drosophila, a maternal effect gene that plays a central role in the establishment of the embryonic dorsal-ventral pattern, has been cloned using P element tagging. A 5.3 kb poly(A)+ ovarian transcript from the cloned region was purified by hybrid selection with the cloned DNA. This purified transcript complements the Toll mutant phenotype when injected into Toll- embryos, which proves that it is the Toll transcript. The sequence of cDNAs suggests that the Toll protein is an integral membrane protein with a cytoplasmic domain and a large extracytoplasmic domain. The putative extracytoplasmic domain contains at least 15 repeats of a 24 amino acid, leucine-rich sequence found in both human and yeast membrane proteins.
果蝇的Toll基因是一种母体效应基因，在胚胎背腹模式的建立中起核心作用，已通过P因子标签法克隆。通过与克隆的DNA进行杂交筛选，从克隆区域纯化出了一个5.3 kb的聚腺苷酸化卵巢转录本。将该纯化的转录本注射到Toll突变胚胎中时，它能弥补Toll突变体表型，这证明它就是Toll转录本。cDNA序列表明，Toll蛋白是一种整合膜蛋白，具有一个胞质结构域和一个大的胞外结构域。推测的胞外结构域至少包含15个重复的24个氨基酸的富含亮氨酸序列，该序列在人和酵母膜蛋白中均有发现。
