Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), 6041, Biopark, Gosselies, Belgium.
Sci Rep. 2021 Feb 26;11(1):4788. doi: 10.1038/s41598-021-83525-1.
The Target of Rapamycin Complex 1 (TORC1) involved in coordination of cell growth and metabolism is highly conserved among eukaryotes. Yet the signals and mechanisms controlling its activity differ among taxa, according to their biological specificities. A common feature of fungal and plant cells, distinguishing them from animal cells, is that their plasma membrane contains a highly abundant H-ATPase which establishes an electrochemical H gradient driving active nutrient transport. We have previously reported that in yeast, nutrient-uptake-coupled H influx elicits transient TORC1 activation and that the plasma-membrane H-ATPase Pma1 plays an important role in this activation, involving more than just establishment of the H gradient. We show here that the PMA2 H-ATPase from the plant Nicotiana plumbaginifolia can substitute for Pma1 in yeast, to promote H-elicited TORC1 activation. This H-ATPase is highly similar to Pma1 but has a longer carboxy-terminal tail binding 14-3-3 proteins. We report that a C-terminally truncated PMA2, which remains fully active, fails to promote H-elicited TORC1 activation. Activation is also impaired when binding of PMA2 to 14-3-3 s is hindered. Our results show that at least some plant plasma-membrane H-ATPases share with yeast Pma1 the ability to promote TORC1 activation in yeast upon H-coupled nutrient uptake.
雷帕霉素靶蛋白复合物 1（TORC1）参与细胞生长和代谢的协调，在真核生物中高度保守。然而，根据其生物学特性，控制其活性的信号和机制在不同类群中有所不同。真菌和植物细胞的一个共同特征是，它们的质膜含有丰富的 H-ATPase，这种酶建立电化学 H 梯度，驱动主动营养物质运输。我们之前曾报道过，在酵母中，与营养物质摄取偶联的 H 内流会引发瞬时 TORC1 激活，而质膜 H-ATPase Pma1 在这种激活中起着重要作用，不仅仅是建立 H 梯度。我们在这里表明，来自植物烟草的 PMA2 H-ATPase可以替代酵母中的 Pma1，促进 H 引发的 TORC1 激活。这种 H-ATPase与 Pma1 非常相似，但具有更长的羧基末端尾巴，结合 14-3-3 蛋白。我们报告说，截短的 C 端 PMA2 仍然具有完全的活性，但不能促进 H 引发的 TORC1 激活。当 PMA2 与 14-3-3 的结合受到阻碍时，激活也会受到损害。我们的结果表明，至少一些植物质膜 H-ATPase 与酵母 Pma1 一样，能够在酵母中促进 H 偶联的营养物质摄取后 TORC1 的激活。
