The poles of E. coli cells are emerging as hubs for major sensory systems, but the polar determinants that allocate their components to the pole are largely unknown. Here, we describe the discovery of a novel protein, TmaR, which localizes to the E. coli cell pole when phosphorylated on a tyrosine residue. TmaR is shown here to control the subcellular localization of the general PTS protein Enzyme I (EI) by preventing it from exerting its activity by binding and polar sequestration, thus regulating sugar uptake and metabolism. Depletion or overexpression of TmaR results in EI release from the pole or enhanced recruitment to the pole, which leads to increasing or decreasing the rate of sugar consumption, respectively. Notably phosphorylation of TmaR is required to release EI and enable its activity. Like TmaR, the ability of EI to be recruited to the pole depends on phosphorylation of one of its tyrosines. In addition to hyperactivity in sugar consumption, the absence of TmaR also leads to detrimental effects on the ability of cells to survive in mild acidic conditions. Our results argue that this survival defect, which is sugar- and EI-dependent, reflects the difficulty of cells lacking TmaR to enter stationary phase. Our study identifies TmaR as the first E. coli protein reported to localize in a tyrosine-dependent manner and to control the activity of other proteins by their polar sequestration and release.

中文翻译：

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TmaR的酪氨酸磷酸化依赖性定位，TmaR是一种新型的大肠杆菌极性蛋白，可通过极性螯合控制主要糖调节剂的活性

大肠杆菌细胞的极点正逐渐成为主要感觉系统的枢纽，但很大程度上未知将其成分分配给极点的极性决定因素。在这里，我们描述了一种新型蛋白质TmaR的发现，该蛋白质在酪氨酸残基上被磷酸化时可定位于大肠杆菌细胞极。此处显示TmaR通过阻止其通过结合和极性螯合发挥其活性，从而调节糖的摄取和代谢，从而控制一般PTS蛋白酶I（EI）的亚细胞定位。TmaR的耗尽或过度表达导致EI从极点释放或增强向极点的募集，这分别导致糖消耗速率的增加或降低。值得注意的是，TmaR的磷酸化需要释放EI并使其具有活性。像TmaR EI募集到极的能力取决于其酪氨酸之一的磷酸化。除了糖消耗的过度活跃之外，TmaR的缺乏还导致对细胞在弱酸性条件下存活的能力的有害影响。我们的研究结果表明，这种生存缺陷是糖和EI依赖性的，反映了缺乏TmaR的细胞进入稳定期的困难。我们的研究确定TmaR为第一个据报道以酪氨酸依赖性方式定位并通过极性螯合和释放控制其他蛋白质活性的大肠杆菌蛋白质。我们的研究结果表明，这种生存缺陷是糖和EI依赖性的，反映了缺乏TmaR的细胞进入稳定期的困难。我们的研究确定TmaR为第一个据报道以酪氨酸依赖性方式定位并通过极性螯合和释放控制其他蛋白质活性的大肠杆菌蛋白质。我们的研究结果表明，这种生存缺陷是糖和EI依赖性的，反映了缺乏TmaR的细胞进入稳定期的困难。我们的研究确定TmaR为第一个据报道以酪氨酸依赖性方式定位并通过极性螯合和释放控制其他蛋白质活性的大肠杆菌蛋白质。