REGULATION OF THE SYNTHESIS OF SURFACE PROTEIN IN THE CELL-CYCLE OF ESCHERICHIA-COLI B-R
REGULATION OF THE SYNTHESIS OF SURFACE PROTEIN IN THE CELL-CYCLE OF ESCHERICHIA-COLI B-R
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DOI：
10.1016/0092-8674(79)90048-5
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发表时间：
1979-01-01
期刊：
影响因子：
64.5
通讯作者：
HOLLAND, IB
中科院分区：
文献类型：
--
作者：
BOYD, A;HOLLAND, IB
对E. coli B/r的细胞周期中，通过测定分离的内外膜蛋白质的合成，研究了细胞周期中内外膜蛋白质的变化。虽然总蛋白质和散装内膜蛋白质的合成连续和在整个周期中以指数增加的速率，散装外膜蛋白质的合成在整个周期中以恒定的速率与分裂前10-15分钟发生的速率突然加倍。当在总细胞裂解物中直接测量单个蛋白质（36.5K [千道尔顿]外膜蛋白）的合成速率时，观察到类似的模式。无论是胸腺嘧啶饥饿，也不影响外膜蛋白的合成的指数文化的基因剂量的变化，这表明在速率倍增是不控制的基因复制机制。其他研究结果进一步表明，外膜蛋白的合成以某种方式受到调节。因此，36.5K孔蛋白/单位表面积的浓度保持恒定，因为表面积/体积比随生长速率变化很大。也获得了直接的证据，整体限制散装外膜蛋白的合成速率。当一类新的外膜蛋白被诱导时，其他表面蛋白的合成速率相应地降低。一个模型，其中的外膜蛋白的线性增长，从限制外膜多肽的合成在翻译水平上，反映了在信封中的基本肽聚糖层的线性扩张进行了讨论。
The biogenesis of the envelope of E. coli B/r was studied by measuring the synthesis of protein in separated inner and outer membranes during the cell cycle. While total protein and bulk inner membrane protein were synthesized continuously and at an exponentially increasing rate throughout the cycle, bulk outer membrane protein was synthesized at a constant rate throughout the cycle with an abrupt doubling in rate occurring 10-15 min before division. A similar pattern was observed when the rate of synthesis of an individual protein, the 36.5K [kilodalton] outer membrane protein, was measured directly in total cell lysates. Neither thymine starvation nor changes in gene dosage of exponential cultures affected the synthesis of outer membrane protein, indicating that the doubling in rate is not controlled by a gene duplication mechanism. Other findings further indicate that outer membrane protein synthesis is regulated in some way. Thus the concentration of 36.5K porin/unit surface area remained constant as the surface area/volume ratio varied widely with growth rate. Direct evidence for an overall limitation on the rate of synthesis of bulk outer membrane proteins was also obtained. When a new class of outer membrane proteins was induced, the rate of synthesis of other surface proteins was correspondingly reduced. A model in which the linear growth of outer membrane protein from a limitation of outer membrane polypeptide synthesis at the translational level, reflecting the linear expansion of the underlying peptidoglycan layer in the envelope is discussed.