家蚕BmFKBP45基因的表达和功能分析

以家蚕（Bombyx mori）为研究对象，对果蝇DmFKBP39的同源蛋白BmFKBP45进行了表达和初步的功能分析. 对DmFKBP39和BmFKBP45进行氨基酸序列比对分析发现，它们都含有酸性氨基酸区域、碱性氨基酸区域、核定位信号及FKBP结构域. 将BmFKBP45的第2个碱性区域与核蛋白HMG2的DNA结合位点进行比对，相似性达到21%，推测BmFKBP45可通过其第2个碱性区域与DNA结合，但EMSA的结果显示重组BmFKBP45不与果蝇的JHRE1元件结合. RT-PCR和Western blot结果显示，BmFKBP45在各个发育时期的家蚕翅原基中都有表达，在蛹期的表达量逐渐下降. 激素处理实验结果显示，BmFKBP45的表达并不受20E和JH的影响. 利用Pull-down、Far-western blot和Co-IP实验鉴定出一个与BmFKBP45相互作用的蛋白Bm6G1. 这些研究结果为进一步探究BmFKBP45的功能提供了线索.

Expression and Functional Analysis of BmFKBP45 in the Silkworm,Bombyx mori

The expression and function of the Drosophila DmFKBP39 homolog in the Silkworm, BmFKBP45, were analyzed in this study. By comparing the amino acid sequences of DmFKBP39 and BmFKBP45, it is found that both of them contained an acidic amino acid region, a basic amino acid region, a nuclear localization signal and a FKBP domain. Alignment for the DNA binding domain of HMG2 with the second basic region of BmFKBP45 shows a similarity of 21%, suggesting that BmFKBP45 may be capable of DNA binding through the second basic amino acid region. However, EMSA experiment showed that BmFKBP45 did not bind to DmJHRE1. The RT-PCR and western blot results indicated that BmFKBP45 expressed at different developmental stages in the silkworm wing disc and its expression decreased gradually during the pupal period. The hormone treatment assays demonstrated that the expression of BmFKBP45 was not changed by either ecdysone (20E) or juvenile hormone (JH). The pull-down, far-western blot and Co-IP experiments indicated an interaction between BmFKBP45 and Bm6G1, which provides a new perspective for further exploring the function of BmFKBP45.