Keegan J, Schmerer M, Ring B, Garza D
Department of Biological Sciences and Program in Medical Sciences, The Florida State University, Tallahassee, FL 32306-4370, USA.
Genet Res. 2001 Feb;77(1):27-39. doi: 10.1017/s0016672300004870.
At the onset of metamorphosis in Drosophila melanogaster, the steroid hormone 20-OH ecdysone induces a small number of early and early-late puffs in the polytene chromosomes of the third-instar larval salivary gland whose activity is required for regulating the activity of a larger set of late puffs. Most of the corresponding early and early-late genes have been found to encode transcription factors that regulate a much larger set of late genes. In contrast, we describe here the identification of an ecdysone-regulated gene in the 62E early-late puff, denoted D-spinophilin, that encodes a protein similar to the mammalian protein spinophilin/neurabin II. The D-spinophilin protein is predicted to contain a highly conserved PP1-binding domain and adjacent PDZ domain, as well as a coiled-coil domain and SAM domain, and belongs to a family of related proteins from diverse organisms. Transcription of D-spinophilin is correlated with 62E puff activity during the early stages of metamorphosis and is ecdysone-dependent, making this the first member of this gene family shown to be regulated by a steroid hormone. Examination of the dynamic patterns of D-spinophilin expression during the early stages of metamorphosis are consistent with a role in central nervous system metamorphosis as well as a more general role in other tissues. As D-spinophilin appears to be the only member of this gene family in Drosophila, its study provides an excellent opportunity to elucidate the role of an important adaptor protein in a genetic model organism.
在黑腹果蝇变态发育开始时，类固醇激素20-羟基蜕皮激素会在三龄幼虫唾液腺的多线染色体中诱导少量早期和早晚期胀泡，这些胀泡的活性对于调节大量晚期胀泡的活性是必需的。已发现大多数相应的早期和早晚期基因编码调节大量晚期基因的转录因子。相比之下，我们在此描述了在62E早晚期胀泡中鉴定出一个蜕皮激素调节基因，命名为D-亲旋蛋白，它编码一种与哺乳动物亲旋蛋白/神经纤蛋白II相似的蛋白质。预测D-亲旋蛋白含有一个高度保守的PP1结合结构域和相邻的PDZ结构域，以及一个卷曲螺旋结构域和SAM结构域，并且属于来自不同生物体的相关蛋白质家族。在变态发育早期，D-亲旋蛋白的转录与62E胀泡活性相关，并且依赖于蜕皮激素，这使得该基因家族的这一成员成为首个被证明受类固醇激素调节的成员。对变态发育早期D-亲旋蛋白表达动态模式的研究表明，它在中枢神经系统变态发育中发挥作用，并且在其他组织中也具有更广泛的作用。由于D-亲旋蛋白似乎是果蝇中该基因家族的唯一成员，对其进行研究为阐明一种重要衔接蛋白在遗传模式生物中的作用提供了绝佳机会。
