Hassan Noman, Murray Brendan G, Jagadeeshan Santosh, Thomas Robert, Katselis George S, Ianowski Juan P
Department of Anatomy Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon S7N 5E5, Canada.
Department of Zoology, St. Joseph's University, Bangalore 560027, India.
iScience. 2023 Dec 4;27(1):108629. doi: 10.1016/j.isci.2023.108629. eCollection 2024 Jan 19.
Since the early seminal studies on epithelial solute transport, it has been understood that there must be crosstalk among different members of the transport machinery to coordinate their activity and, thus, generate localized electrochemical gradients that force solute flow in the required direction that would otherwise be thermodynamically unfavorable. However, mechanisms underlying intracellular crosstalk remain unclear. We present evidence that crosstalk between apical and basolateral membrane transporters is mediated by intracellular Ca signaling in insect renal epithelia. Ion flux across the basolateral membrane is encoded in the intracellular Ca oscillation frequency and amplitude modulation and that information is used by the apical membrane to adjust ion flux accordingly. Moreover, imposing experimentally generated intracellular Ca oscillation modulation causes cells to predictably adjust their ion transport properties. Our results suggest that intracellular Ca oscillation frequency and amplitude modulation encode information on transmembrane ion flux that is required for crosstalk.
自早期关于上皮溶质转运的开创性研究以来，人们就已明白，转运机制的不同成员之间必定存在相互作用，以协调它们的活性，从而产生局部电化学梯度，迫使溶质沿所需方向流动，否则在热力学上是不利的。然而，细胞内相互作用的潜在机制仍不清楚。我们提供的证据表明，昆虫肾上皮细胞顶膜和基底外侧膜转运体之间的相互作用是由细胞内钙信号介导的。跨基底外侧膜的离子通量编码在细胞内钙振荡频率和幅度调制中，而顶膜利用该信息相应地调节离子通量。此外，施加实验性产生的细胞内钙振荡调制会使细胞可预测地调整其离子转运特性。我们的结果表明，细胞内钙振荡频率和幅度调制编码了相互作用所需的跨膜离子通量信息。
