
Aquaporin
Aquaporins are transmembrane channels that are widely expressed in various cells and tissues of different organisms. These highly selective water transport channels play a crucial role in facilitating the passive movement of water across cell membranes, thereby maintaining the water balance and osmoregulation within living organisms. Aquaporins exhibit a diverse range of structural variations that contribute to their specificity for different cell types and tissues. This channel is composed of six membrane-spanning helices that form distinct channels for water transport. The channel pore includes key residues such as Arg, which prevent the entry of other molecules, including protons. The NPA motifs found in the lower helices help to maintain a uniform 1-2-1 water profile along the channel cavity. These proteins are involved in several biological processes. They contribute to maintaining cell turgidity in plants, concentrating urine in mammals, regulating cerebrospinal fluid dynamics, and facilitating the secretion and absorption of fluids in various tissues. Dysregulation of aquaporins has been associated with various health conditions such as nephrogenic diabetes insipidus, cerebral edema, Alzheimer's disease, and neuromyelitis optica. Our research focused on the dynamics and function of aquaporin channels and their association with various diseases. We employed extensive molecular dynamics simulations and associated techniques to understand the structural and functional dynamics of aquaporins, complemented by experimental studies. One significant aspect of our research highlights the role of aquaporin-2 in nephrogenic diabetes insipidus induced by exposure to T-2 toxin and its connection to induced cerebral edema. Our simulation studies have revealed critical residues apart from Arg in the pore region, such as His, Ala, and Phe, which control pore diameter. Furthermore, our research delves into aquaporin-4-mediated aggregation of Alzheimer's amyloid peptides. We observed that aquaporin-4 helped reduce the aggregation of amyloid beta peptides by maintaining their helical content. An ongoing area of investigation involves exploring the colocalization of aquaporin channels with other proteins and channels in the brain. Through our research efforts, we aimed to deepen our understanding of aquaporin dynamics, their functional significance, and their implications in various diseases.