Cowan Ann E, Koppel Dennis E, Setlow Barbara, Setlow Peter
Center for Biomedical Imaging Technology, University of Connecticut Health Center, Farmington, CT 06032, USA.
Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):4209-14. doi: 10.1073/pnas.0636762100. Epub 2003 Mar 19.
Fluorescence redistribution after photobleaching has been used to show that a cytoplasmic GFP fusion is immobile in dormant spores of Bacillus subtilis but becomes freely mobile in germinated spores in which cytoplasmic water content has increased approximately 2-fold. The GFP immobility in dormant spores is not due to the high levels of dipicolinic acid in the spore cytoplasm, because GFP was also immobile in germinated cwlD spores that had excreted their dipicolinic acid but where cytoplasmic water content had only increased to a level similar to that in dormant spores of several other Bacillus species. The immobility of a normally mobile protein in dormant wild-type spores and germinated cwlD spores is consistent with the lack of metabolism and enzymatic activity in these spores and suggests that protein immobility, presumably due to low water content, is a major reason for the metabolic dormancy of spores of Bacillus species.
光漂白后的荧光再分布已被用于表明，细胞质绿色荧光蛋白（GFP）融合蛋白在枯草芽孢杆菌的休眠孢子中是不可移动的，但在萌发的孢子中变得可自由移动，其中细胞质含水量增加了约2倍。休眠孢子中GFP的不可移动并非由于孢子细胞质中高水平的吡啶二羧酸，因为GFP在已排出其吡啶二羧酸但细胞质含水量仅增加到与其他几种芽孢杆菌休眠孢子中相似水平的萌发cwlD孢子中也是不可移动的。正常可移动蛋白在休眠野生型孢子和萌发cwlD孢子中的不可移动与这些孢子中缺乏代谢和酶活性一致，并表明蛋白不可移动，可能是由于含水量低，是芽孢杆菌属孢子代谢休眠的主要原因。
