Helical distribution of the bacterial chemoreceptor via colocalization with the Sec protein translocation machinery.
Helical distribution of the bacterial chemoreceptor via colocalization with the Sec protein translocation machinery.
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DOI：
10.1111/j.1365-2958.2006.05145.x
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发表时间：
2006-05
影响因子：
3.6
通讯作者：
Kawagishi I
中科院分区：
文献类型：
--
作者：
Shiomi D;Yoshimoto M;Homma M;Kawagishi I
在大肠杆菌中，在细胞极的化学感受器集群似乎对信号放大和适应至关重要。然而，很少有人知道本地化本身的机制。在这里，我们研究了天冬氨酸化学受体（焦油）是否直接插入到极性膜，通过使用其融合到绿色荧光蛋白（GFP）。在Tar-GFP诱导后，荧光点首先出现在侧膜区域，随后细胞两极变得主要荧光。出乎意料的是，Tar-GFP在横向区域中显示出螺旋排列，这在周质结构域中具有两个半胱氨酸残基的Tar-GFP衍生物交联形成更高的寡聚体时更明显。此外，即使当双半胱氨酸Tar-GFP突变体的胞质结构域被不定位于极点的激酶EnvZ的胞质结构域取代时，也观察到类似的分布。GFP-SecE和易位缺陷的MalE-GFP突变体的观察，以及SecG的间接免疫荧光显微镜，表明一般蛋白质易位机制（Sec）本身被安排成螺旋阵列，焦油是瞬时相关的。Sec螺旋与肌动蛋白样细胞骨架MreB螺旋不同。这些发现将为阐明大肠杆菌膜蛋白空间组织的机制提供新的思路。杆菌
In Escherichia coli, chemoreceptor clustering at a cell pole seems critical for signal amplification and adaptation. However, little is known about the mechanism of localization itself. Here we examined whether the aspartate chemoreceptor (Tar) is inserted directly into the polar membrane by using its fusion to green fluorescent protein (GFP). After induction of Tar–GFP, fluorescent spots first appeared in lateral membrane regions, and later cell poles became predominantly fluorescent. Unexpectedly, Tar–GFP showed a helical arrangement in lateral regions, which was more apparent when a Tar–GFP derivative with two cysteine residues in the periplasmic domain was cross-linked to form higher oligomers. Moreover, similar distribution was observed even when the cytoplasmic domain of the double cysteine Tar–GFP mutant was replaced by that of the kinase EnvZ, which does not localize to a pole. Observation of GFP–SecE and a translocation-defective MalE–GFP mutant, as well as indirect immunofluorescence microscopy on SecG, suggested that the general protein translocation machinery (Sec) itself is arranged into a helical array, with which Tar is transiently associated. The Sec coil appeared distinct from the MreB coil, an actin-like cytoskeleton. These findings will shed new light on the mechanisms underlying spatial organization of membrane proteins in E. coli.
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影响因子：
6.8
作者：
Falke, JJ;Kim, SH
通讯作者：
Kim, SH
DOI：
10.1073/pnas.092071899
发表时间：
2002-05-14
影响因子：
11.1
作者：
Ames, P;Studdert, CA;Parkinson, JS
通讯作者：
Parkinson, JS
影响因子：
64.8
作者：
BASSFORD, P;BECKWITH, J
通讯作者：
BECKWITH, J
DOI：
10.1073/pnas.0306660101
发表时间：
2004-03-09
影响因子：
11.1
作者：
Homma, M;Shiomi, D;Kawagishi, I
通讯作者：
Kawagishi, I
影响因子：
3.2
作者：
GUZMAN, LM;BELIN, D;BECKWITH, J
通讯作者：
BECKWITH, J