Facultat de Medicina, Departament de Ciències Fisiològiques, Universitat de Barcelona-IDIBELL, C/Feixa Llarga s/n, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
Centro de Investigación en red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), 08907 Barcelona, Spain.
Int J Mol Sci. 2018 Mar 2;19(3):719. doi: 10.3390/ijms19030719.
Volume-regulated anion channels (VRACs) play a role in controlling cell volume by opening upon cell swelling. Apart from controlling cell volume, their function is important in many other physiological processes, such as transport of metabolites or drugs, and extracellular signal transduction. VRACs are formed by heteromers of the pannexin homologous protein LRRC8A (also named Swell1) with other LRRC8 members (B, C, D, and E). LRRC8 proteins are difficult to study, since they are expressed in all cells of our body, and the channel stoichiometry can be changed by overexpression, resulting in non-functional heteromers. Two different strategies have been developed to overcome this issue: complementation by transient transfection of LRRC8 genome-edited cell lines, and reconstitution in lipid bilayers. Alternatively, we have used oocytes as a simple system to study LRRC8 proteins. Here, we have reviewed all previous experiments that have been performed with VRAC and LRRC8 proteins in oocytes. We also discuss future strategies that may be used to perform structure-function analysis of the VRAC in oocytes and other systems, in order to understand its role in controlling multiple physiological functions.
容积调节阴离子通道（VRAC）在细胞肿胀时开启，从而在控制细胞体积方面发挥作用。除了控制细胞体积外，其功能在许多其他生理过程中也很重要，例如代谢物或药物的运输以及细胞外信号转导。VRAC 由 pannexin 同源蛋白 LRRC8A（也称为 Swell1）与其他 LRRC8 成员（B、C、D 和 E）的异源二聚体组成。LRRC8 蛋白难以研究，因为它们在我们身体的所有细胞中表达，并且通道的化学计量可以通过过表达而改变，从而导致非功能性异源二聚体。已经开发出两种不同的策略来克服这个问题：通过瞬时转染 LRRC8 基因编辑细胞系进行互补，以及在脂质双层中重建。或者，我们使用卵母细胞作为研究 LRRC8 蛋白的简单系统。在这里，我们回顾了在卵母细胞中使用 VRAC 和 LRRC8 蛋白进行的所有先前实验。我们还讨论了未来可能用于在卵母细胞和其他系统中进行 VRAC 的结构-功能分析的策略，以了解其在控制多种生理功能中的作用。
