Type V Myosin focuses the polarisome and shapes the tip of yeast cells
Type V Myosin focuses the polarisome and shapes the tip of yeast cells
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V 型肌球蛋白聚焦极化体并塑造酵母细胞的尖端
DOI：
10.1101/2020.07.09.195271
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Dünkler A
中科院分区：
文献类型：
--
作者：
Dünkler A
极化体是一个皮质蛋白微室，它组织肌动蛋白细丝的生长和酵母和丝状真菌中分泌小泡的融合。极化体是紧密的、斑点状的结构，位于各自细胞的生长顶端。控制这个微格的形状和大小的分子作用力尚不清楚。在这里，我们确定了极化体亚单位Pea2和V型肌球蛋白Myo2之间的复合体，它将Myo2锚定在酵母细胞的皮质上。我们在Myo2的货物结合区发现了一个点突变，它损害了与Pea2的相互作用，从而影响了极化体的形成和焦点定位。携带这种突变的细胞长得是圆形的，而不是细长的花蕾。进一步的实验和生物物理模拟表明，极化体结合的MyO2马达和动态肌动蛋白细丝之间的相互作用在空间上聚焦于极化体并维持其紧凑的形状。
The polarisome is a cortical proteinaceous microcompartment that organizes the growth of actin filaments and the fusion of secretory vesicles in yeasts and filamentous fungi. Polarisomes are compact, spotlike structures at the growing tips of their respective cells. The molecular forces that control the form and size of this microcompartment are not known. Here we identify a complex between the polarisome subunit Pea2 and the type V Myosin Myo2 that anchors Myo2 at the cortex of yeast cells. We discovered a point mutation in the cargo-binding domain of Myo2 that impairs the interaction with Pea2 and consequently the formation and focused localization of the polarisome. Cells carrying this mutation grow round instead of elongated buds. Further experiments and biophysical modeling suggest that the interactions between polarisome-bound Myo2 motors and dynamic actin filaments spatially focus the polarisome and sustain its compact shape.