柞蚕14-3-3基因的鉴定及表达分析

14-3-3蛋白是一种可以改变其结合蛋白构象的酸性蛋白质.柞蚕14-3-3 cDNA序列全长1 220 bp,包括一个126 bp的5'非编码区和一个350 bp的3'非编码区.该基因的开放读码框长度为744 bp,编码247个氨基酸.序列比对结果表明,柞蚕14-3-3蛋白与家蚕的14-3-3蛋白具有高度同源性.此外对柞蚕14-3-3基因进行了原核表达和重组蛋白纯化.SDS-PAGE和免疫印迹结果表明,分子量大小约32 kD的重组蛋白在大肠杆菌中得到了成功表达.     

A slicer for polyacrylamide gels of 3-, 6-, and 18-mm diameter.

A new gel sectioning device for polyacrylamide gel electrophoresis (PAGE) utilizing an iris diaphragm type of concentric cutting blade has been recently described (1). Although gel cylinders of 5- or 6-mm diam are most often used, cylinders of other diameters are often utilized for purposes of sample economy or ease of preparation. The versatile single cutting device described here enables sectioning of PAGE cylinders having 3-, 6-, or 18-mm diam; it can be easily adapted to accept gels with diameters less than 18 mm.     

Pherokine-2 and -3.

Drosophila is a powerful model system to study the regulatory and effector mechanisms of innate immunity. To identify molecules induced in the course of viral infection in this insect, we have developed a model based on intrathoracic injection of the picorna-like Drosophila C virus (DCV). We have used MALDI-TOF mass spectrometry to compare the hemolymph of DCV infected flies and control flies. By contrast with the strong humoral response triggered by injection of bacteria or fungal spores, we have identified only one molecule induced in the hemolymph of virus infected flies. This molecule, pherokine-2 (Phk-2), is related to OS-D/A10 (Phk-1), which was previously characterized as a putative odor/pheromone binding protein specifically expressed in antennae. The virus-induced molecule is also similar to the product of the gene CG9358 (Phk-3), which is induced by septic injury. Both Phk-2 and Phk-3 are strongly expressed during metamorphosis, suggesting that they may participate in tissue-remodeling.     

Fusicoccin, 14-3-3 proteins, and defense responses in tomato plants

Fusicoccin (FC) is a fungal toxin that activates the plant plasma membrane H+-ATPase by binding with 14-3-3 proteins, causing membrane hyperpolarization. Here we report on the effect of FC on a gene-for-gene pathogen-resistance response and show that FC application induces the expression of several genes involved in plant responses to pathogens. Ten members of the FC-binding 14-3-3 protein gene family were isolated from tomato (Lycopersicon esculentum) to characterize their role in defense responses. Sequence analysis is suggestive of common biochemical functions for these tomato 14-3-3 proteins, but their genes showed different expression patterns in leaves after challenges. Different specific subsets of 14-3-3 genes were induced after treatment with FC and during a gene-for-gene resistance response. Possible roles for the H+-ATPase and 14-3-3 proteins in responses to pathogens are discussed.