Institut Curie, PSL Research University, CNRS, UMR 168, Paris, France.
Institut Curie, PSL Research University, CNRS, UMR 168, Paris, France.
Biophys J. 2018 Feb 27;114(4):947-957. doi: 10.1016/j.bpj.2017.12.018.
The dynamical organization of membrane-bound organelles along intracellular transport pathways relies on vesicular exchange between organelles and on the maturation of the organelle's composition by enzymatic reactions or exchange with the cytoplasm. The relative importance of each mechanism in controlling organelle dynamics remains controversial, in particular for transport through the Golgi apparatus. Using a stochastic model, we identify two classes of dynamical behavior that can lead to full maturation of membrane-bound compartments. In the first class, maturation corresponds to the stochastic escape from a steady state in which export is dominated by vesicular exchange, and is very unlikely for large compartments. In the second class, it occurs in a quasi-deterministic fashion and is almost size independent. Whether a system belongs to the first or second class is largely controlled by homotypic fusion.
膜结合细胞器在细胞内运输途径中的动态组织依赖于细胞器之间的小泡交换，以及通过酶反应或与细胞质交换来实现细胞器组成的成熟。每种机制在控制细胞器动力学方面的相对重要性仍然存在争议，特别是对于通过高尔基体的运输。使用随机模型，我们确定了两种可以导致膜结合隔室完全成熟的动力学行为。在第一类中，成熟对应于从以小泡交换为主导的出口的稳定状态的随机逃逸，对于大隔室来说，这种情况极不可能发生。在第二类中，它以准确定性的方式发生，几乎与大小无关。一个系统属于第一类还是第二类在很大程度上取决于同源融合。
