Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
VIB Center for Plant Systems Biology, 9052 Ghent, Belgium.
Proc Natl Acad Sci U S A. 2021 Apr 13;118(15). doi: 10.1073/pnas.2023456118.
In plants, endocytosis is essential for many developmental and physiological processes, including regulation of growth and development, hormone perception, nutrient uptake, and defense against pathogens. Our toolbox to modulate this process is, however, rather limited. Here, we report a conditional tool to impair endocytosis. We generated a partially functional TPLATE allele by substituting the most conserved domain of the TPLATE subunit of the endocytic TPLATE complex (TPC). This substitution destabilizes TPC and dampens the efficiency of endocytosis. Short-term heat treatment increases TPC destabilization and reversibly delocalizes TPLATE from the plasma membrane to aggregates in the cytoplasm. This blocks FM uptake and causes accumulation of various known endocytic cargoes at the plasma membrane. Short-term heat treatment therefore transforms the partially functional TPLATE allele into an effective conditional tool to impair endocytosis. Next to their role in endocytosis, several TPC subunits are also implicated in actin-regulated autophagosomal degradation. Inactivating TPC via the WDX mutation, however, does not impair autophagy, thus enabling specific and reversible modulation of endocytosis in planta.
在植物中，内吞作用对于许多发育和生理过程是必不可少的，包括生长和发育的调节、激素感知、营养物质吸收和抵御病原体。然而，我们调节这个过程的工具相当有限。在这里，我们报告了一种用于削弱内吞作用的条件性工具。我们通过替换内吞体 TPLATE 复合物 (TPC) 的 TPLATE 亚基的最保守结构域，生成了一个部分功能的 TPLATE 等位基因。这种取代会使 TPC 不稳定，并降低内吞作用的效率。短期热处理会增加 TPC 的不稳定性，并将 TPLATE 从质膜可逆地重新定位到细胞质中的聚集体中。这会阻止 FM 摄取，并导致各种已知的内吞货物在质膜处积累。因此，短期热处理将部分功能的 TPLATE 等位基因转化为一种有效的条件性工具，用于削弱内吞作用。除了在内吞作用中的作用外，几个 TPC 亚基还与肌动蛋白调节的自噬体降解有关。然而，通过 WDX 突变使 TPC 失活并不会损害自噬，从而能够在植物体内特异性和可逆地调节内吞作用。
