Glomb Oliver, Bareis Lara, Johnsson Nils
Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, James-Franck-Ring N27, D-89081 Ulm, Germany.
Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, James-Franck-Ring N27, D-89081 Ulm, Germany
Biol Open. 2019 Aug 9;8(8):bio044024. doi: 10.1242/bio.044024.
The polarisome comprises a network of proteins that organizes polar growth in yeast and filamentous fungi. The yeast formin Bni1 and the actin nucleation-promoting factor Bud6 are subunits of the polarisome that together catalyze the formation of actin cables below the tip of yeast cells. We identified YFR016c (Aip5) as an interaction partner of Bud6 and the polarisome scaffold Spa2. Yeast cells lacking Aip5 display a reduced number of actin cables. Aip5 binds with its N-terminal region to Spa2 and with its C-terminal region to Bud6. Both interactions collaborate to localize Aip5 at bud tip and neck, and are required to stimulate the formation of actin cables. Our experiments characterize Aip5 as a novel subunit of a complex that regulates the number of actin filaments at sites of polar growth.
极化体由一个蛋白质网络组成，该网络在酵母和丝状真菌中组织极性生长。酵母formin蛋白Bni1和肌动蛋白成核促进因子Bud6是极化体的亚基，它们共同催化酵母细胞顶端下方肌动蛋白电缆的形成。我们鉴定出YFR016c（Aip5）是Bud6和极化体支架Spa2的相互作用伙伴。缺乏Aip5的酵母细胞显示出肌动蛋白电缆数量减少。Aip5的N端区域与Spa2结合，C端区域与Bud6结合。这两种相互作用共同作用将Aip5定位在芽尖和颈部，并且是刺激肌动蛋白电缆形成所必需的。我们的实验将Aip5表征为一种复合物的新型亚基，该复合物在极性生长位点调节肌动蛋白丝的数量。
