Lazdunski C J, Benedetti H
Centre de Biochemie et de Biologie Moléculaire du CNRS, Marseille, France.
FEBS Lett. 1990 Aug 1;268(2):408-14. doi: 10.1016/0014-5793(90)81295-y.
In prokaryotic and eukaryotic organisms, proteins are efficiently sorted to reach their final destinations in a whole range of subcellular compartments. Targeting is mediated by hydrophobic signal sequences or hydrophilic targeting sequences depending upon the compartment, these sequences being often processed. Proteins cannot be translocated through a membrane in a tightly folded stage, they must have a loose conformation, the so-called 'translocation competent state', which is usually kept through interactions with chaperones. In addition to these cytosolic receptor-like components, receptors are also present on the target membranes. Depending upon the organelles and organisms, two different energy sources have been identified, energy rich phosphate bonds (ATP and GTP) and a potential across the target membrane. Besides the signal peptides, various classes of signals have been identified to account for topologies of membrane proteins. Protein secretion in bacterial organisms has been extensively studied. Various classes of proteins use different strategies, some of these may also be used in eukaryotic cells.
在原核生物和真核生物中，蛋白质能够被有效地分选，以到达细胞内各个亚细胞区室的最终目的地。分选是由疏水信号序列或亲水性靶向序列介导的，具体取决于区室，这些序列通常会被加工处理。蛋白质在紧密折叠状态下无法穿过膜，它们必须具有松散的构象，即所谓的“易位活性状态”，这种状态通常通过与伴侣蛋白的相互作用得以维持。除了这些胞质受体样成分外，靶膜上也存在受体。根据细胞器和生物体的不同，已确定了两种不同的能量来源，即富含能量的磷酸键（ATP和GTP）以及靶膜两侧的电位。除了信号肽外，还鉴定出了各类信号来解释膜蛋白的拓扑结构。细菌中的蛋白质分泌已得到广泛研究。各类蛋白质使用不同的策略，其中一些策略也可能在真核细胞中使用。
