Modification of GerQ reveals a functional relationship between Tgl and YabG in the coat of Bacillus subtilis spores
Modification of GerQ reveals a functional relationship between Tgl and YabG in the coat of Bacillus subtilis spores
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DOI：
10.1093/jb/mvj096
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发表时间：
2006-05-01
影响因子：
2.7
通讯作者：
Watabe, Kazuhito
中科院分区：
文献类型：
--
作者：
Kuwana, Ritsuko;Okuda, Naoyuki;Watabe, Kazuhito
在这里，我们描述了YabG和谷氨酰胺转酶（Tg1）之间的功能关系，Tg1是修饰枯草芽孢杆菌孢子外壳蛋白的酶。在37℃的野生型孢子中，Tg1介导GerQ交联成更高的分子质量形式；然而，在tg1突变体孢子中发现了一些GerQ多聚体，这表明tg1不是必需的。免疫印迹显示，37℃产孢后从yabG突变体分离的孢子只含有极低水平的GerQ多聚体。在60℃下加热20分钟，最大限度地激活Tg1的酶活性，在分离的yabG孢子中引起GerQ交联，但在tgl/yabG双突变孢子中没有。此外，在60℃下，l -丙氨酸存在或不存在热激活的情况下，tgl/yabG孢子的萌发率均低于野生型孢子。这些发现表明，Tg1与YabG共同介导了枯草芽孢杆菌外壳蛋白的温度依赖性修饰，这一过程与孢子萌发有关。
Here we describe the functional relationship between YabG and transglutaminase (Tg1), enzymes that modify the spore coat proteins of Bacillus subtilis. In wild-type spores at 37 degrees C, Tg1 mediates the crosslinking of GerQ into higher molecular mass forms; however, some GerQ multimers are found in tg1 mutant spores, indicating that Tg1 is not essential. Immunoblotting showed that spores isolated from a yabG mutant after sporulation at 37 degrees C contain only very low levels of GerQ multimers. Heat treatment for 20 min at 60 degrees C, which maximally activates the enzymatic activity of Tg1, caused crosslinking of GerQ in isolated yabG spores but not in tgl/yabG double-mutant spores. In addition, the germination frequency of the tgl/yabG spores in the presence of L-alanine with or without heat activation at 60 degrees C was lower than that of wild-type spores. These findings suggest that Tg1 cooperates with YabG to mediate the temperature-dependent modification of the coat proteins, a process associated with spore germination in B. subtilis.