Vallesi Adriana, Alimenti Claudio, Pedrini Bill, Di Giuseppe Graziano, Dini Fernando, Wüthrich Kurt, Luporini Pierangelo
Dipartimento di Scienze Ambientali e Naturali, University of Camerino, 62032 Camerino-MC, Italy.
Mar Genomics. 2012 Dec;8:9-13. doi: 10.1016/j.margen.2012.03.004. Epub 2012 May 1.
In protozoan ciliates, diffusible signalling proteins (pheromones) regulate the vegetative growth and mating interactions. Here, the coding genes and the structures of the encoded pheromones were studied in genetically distinct wild-type strains representing interbreeding Antarctic and Arctic populations of the marine ciliate Euplotes nobilii. Determination of seven allelic pheromone-coding DNA sequences revealed that an unusual extension and high structural conservation of the 5' non-coding region are peculiar traits of this gene family, implying that this region is directly involved in the mechanism of pheromone gene expression, possibly through phenomena of intron splicing and/or frame-shifting. For four pheromones, the three-dimensional structures were determined by nuclear magnetic resonance spectroscopy in solution. These structures show that the pheromones represent a protein family which adapts to its polar environment by combining a structurally stable core of a three-helix bundle with extended polypeptide segments that are devoid of regular secondary structures and concomitantly show enhanced structural flexibility.
在原生动物纤毛虫中，可扩散的信号蛋白（信息素）调节营养生长和交配相互作用。在此，我们研究了代表海洋纤毛虫高贵游仆虫（Euplotes nobilii）杂交的南极和北极种群的遗传上不同的野生型菌株中信息素的编码基因及其结构。七个等位基因信息素编码DNA序列的测定表明，5'非编码区的异常延伸和高度结构保守是该基因家族的独特特征，这意味着该区域可能通过内含子剪接和/或移码现象直接参与信息素基因表达机制。对于四种信息素，通过溶液中的核磁共振光谱确定了其三维结构。这些结构表明，信息素代表了一个蛋白质家族，该家族通过将三螺旋束的结构稳定核心与缺乏规则二级结构并同时表现出增强结构灵活性的延伸多肽片段相结合，从而适应其极地环境。
