Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112.
Department of Mathematics, University of Utah, Salt Lake City, UT 84112.
Mol Biol Cell. 2018 Aug 15;29(17):2113-2127. doi: 10.1091/mbc.E17-11-0691. Epub 2018 Jun 21.
Eisosomes are lipid domains of the yeast plasma membrane that share similarities to caveolae of higher eukaryotes. Eisosomes harbor APC-type nutrient transporters for reasons that are poorly understood. Our analyses support the model that eisosomes function as storage compartments, keeping APC transporters in a stable, inactive state. By regulating eisosomes, yeast is able to balance the number of proton-driven APC transporters with the proton-pumping activity of Pma1, thereby maintaining the plasma membrane proton gradient. Environmental or metabolic changes that disrupt the proton gradient cause the rapid restructuring of eisosomes and results in the removal of the APC transporters from the cell surface. Furthermore, we show evidence that eisosomes require the presence of APC transporters, suggesting that regulating activity of nutrient transporters is a major function of eisosomes.
质膜窖（Eisosomes）是酵母质膜的脂质区室，与高等真核生物的质膜窖（caveolae）具有相似性。质膜窖含有 APC 型营养转运蛋白，但具体原因尚不清楚。我们的分析支持这样一种模型，即质膜窖作为储存室，使 APC 转运蛋白保持稳定、非活跃的状态。通过调节质膜窖，酵母能够平衡质子驱动的 APC 转运蛋白的数量与 Pma1 的质子泵活性，从而维持质膜质子梯度。破坏质子梯度的环境或代谢变化会导致质膜窖迅速重构，并导致 APC 转运蛋白从细胞表面去除。此外，我们还提供了证据表明质膜窖需要 APC 转运蛋白的存在，这表明调节营养转运蛋白的活性是质膜窖的主要功能之一。
