Wood Janet M
Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Sci STKE. 2006 Oct 17;2006(357):pe43. doi: 10.1126/stke.3572006pe43.
Osmosensors are proteins that sense environmental osmotic pressure. They mediate or direct osmoregulatory responses that allow cells to survive osmotic changes and extremes. Bacterial osmosensing transporters sense high external osmotic pressure and respond by mediating organic osmolyte uptake, hence cellular rehydration. Detailed studies of osmosensing transporters OpuA, BetP, and ProP suggest that they sense and respond to different osmotic pressure-dependent cellular properties. These studies also suggest that each protein has a cytoplasmic osmosensory or osmoregulatory domain, but that these domains differ in structure and function. It is not yet clear whether each transporter represents a distinct osmosensory mechanism or whether different research groups are approaching the same mechanism by way of different paths. Principles emerging from this research will apply to other osmosensors, including those that initiate signal transduction cascades in prokaryotes and eukaryotes.
渗透感受器是感知环境渗透压的蛋白质。它们介导或直接引发渗透调节反应，使细胞能够在渗透压变化和极端情况下存活。细菌渗透感应转运蛋白感知外部高渗透压，并通过介导有机渗透溶质的摄取做出反应，从而实现细胞再水化。对渗透感应转运蛋白OpuA、BetP和ProP的详细研究表明，它们感知并响应不同的渗透压依赖性细胞特性。这些研究还表明，每种蛋白质都有一个细胞质渗透感应或渗透调节结构域，但这些结构域在结构和功能上有所不同。目前尚不清楚每种转运蛋白是否代表一种独特的渗透感应机制，或者不同的研究小组是否通过不同的途径研究相同的机制。这项研究中出现的原理将适用于其他渗透感受器，包括那些在原核生物和真核生物中启动信号转导级联反应的渗透感受器。
