Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA.
California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA.
J Cell Biol. 2021 Dec 6;220(12). doi: 10.1083/jcb.202108105. Epub 2021 Oct 18.
The endoplasmic reticulum (ER) carries out essential and conserved cellular functions, which depend on the maintenance of its structure and subcellular distribution. Here, we report developmentally regulated changes in ER morphology and composition during budding yeast meiosis, a conserved differentiation program that gives rise to gametes. A subset of the cortical ER collapses away from the plasma membrane at anaphase II, thus separating into a spatially distinct compartment. This programmed collapse depends on the transcription factor Ndt80, conserved ER membrane structuring proteins Lnp1 and reticulons, and the actin cytoskeleton. A subset of ER is retained at the mother cell plasma membrane and excluded from gamete cells via the action of ER-plasma membrane tethering proteins. ER remodeling is coupled to ER degradation by selective autophagy, which relies on ER collapse and is regulated by timed expression of the autophagy receptor Atg40. Thus, developmentally programmed changes in ER morphology determine the selective degradation or inheritance of ER subdomains by gametes.
内质网 (ER) 执行重要且保守的细胞功能，这依赖于其结构和亚细胞分布的维持。在这里，我们报告了在芽殖酵母减数分裂过程中 ER 形态和组成的发育调控变化，减数分裂是一个保守的分化程序，产生配子。在后期 II 时，皮质 ER 的一部分从质膜坍塌，从而分离成一个空间上不同的隔室。这种程序性的坍塌依赖于转录因子 Ndt80、保守的 ER 膜结构蛋白 Lnp1 和 reticulons 以及肌动蛋白细胞骨架。一部分 ER 保留在母细胞质膜上，并通过 ER-质膜连接蛋白的作用排除在配子细胞之外。ER 重塑与选择性自噬耦联，这依赖于 ER 坍塌，并受自噬受体 Atg40 的定时表达调控。因此，ER 形态的发育编程变化决定了 ER 亚域通过配子的选择性降解或遗传。
