Saraste Jaakko, Prydz Kristian
Department of Biomedicine and Molecular Imaging Center, University of Bergen, Bergen, Norway.
Department of Biosciences, University of Oslo, Oslo, Norway.
Front Cell Dev Biol. 2019 Aug 21;7:171. doi: 10.3389/fcell.2019.00171. eCollection 2019.
A characteristic feature of vertebrate cells is a Golgi ribbon consisting of multiple cisternal stacks connected into a single-copy organelle next to the centrosome. Despite numerous studies, the mechanisms that link the stacks together and the functional significance of ribbon formation remain poorly understood. Nevertheless, these questions are of considerable interest, since there is increasing evidence that Golgi fragmentation - the unlinking of the stacks in the ribbon - is intimately connected not only to normal physiological processes, such as cell division and migration, but also to pathological states, including neurodegeneration and cancer. Challenging a commonly held view that ribbon architecture involves the formation of homotypic tubular bridges between the Golgi stacks, we present an alternative model, based on direct interaction between the biosynthetic (pre-Golgi) and endocytic (post-Golgi) membrane networks and their connection with the centrosome. We propose that the central domains of these permanent pre- and post-Golgi networks function together in the biogenesis and maintenance of the more transient Golgi stacks, and thereby establish "linker compartments" that dynamically join the stacks together. This model provides insight into the reversible fragmentation of the Golgi ribbon that takes place in dividing and migrating cells and its regulation along a cell surface - Golgi - centrosome axis. Moreover, it helps to understand transport pathways that either traverse or bypass the Golgi stacks and the positioning of the Golgi apparatus in differentiated neuronal, epithelial, and muscle cells.
脊椎动物细胞的一个特征是高尔基体带，它由多个扁平囊堆叠组成，这些堆叠连接成一个位于中心体附近的单拷贝细胞器。尽管进行了大量研究，但将这些堆叠连接在一起的机制以及高尔基体带形成的功能意义仍知之甚少。然而，这些问题相当引人关注，因为越来越多的证据表明，高尔基体碎片化——高尔基体带中堆叠的分离——不仅与正常生理过程密切相关，如细胞分裂和迁移，还与病理状态有关，包括神经退行性变和癌症。我们挑战了一种普遍观点，即高尔基体带结构涉及高尔基体堆叠之间同型管状桥的形成，而是基于生物合成（前高尔基体）和内吞（后高尔基体）膜网络之间的直接相互作用及其与中心体的连接，提出了一种替代模型。我们认为，这些永久性的前高尔基体和后高尔基体网络的中央结构域在更短暂的高尔基体堆叠的生物发生和维持中共同发挥作用，从而建立起将堆叠动态连接在一起的“连接隔室”。该模型为在分裂和迁移细胞中发生的高尔基体带的可逆碎片化及其沿细胞表面 - 高尔基体 - 中心体轴的调节提供了见解。此外，它有助于理解穿过或绕过高尔基体堆叠的运输途径以及高尔基体在分化的神经元、上皮和肌肉细胞中的定位。
