The Expanding Role of Vesicles Containing Aquaporins

Abstract

In animals and plants, membrane vesicles containing proteins have been defined as key for biological systems involving different processes such as trafficking or intercellular communication. Docking and fusion of vesicles to the plasma membrane occur in living cells in response to different stimuli, such as environmental changes or hormones, and therefore play an important role in cell homeostasis as vehicles for certain proteins or other substances. Because aquaporins enhance the water permeability of membranes, their role as proteins immersed in vesicles formed of natural membranes is a recent topic of study. They regulate numerous physiological processes and could hence serve new biotechnological purposes. Thus, in this review, we have explored the physiological implications of the trafficking of aquaporins, the mechanisms that control their transit, and the proteins that coregulate the migration. In addition, the importance of exosomes containing aquaporins in the cell-to-cell communication processes in animals and plants have been analyzed, together with their potential uses in biomedicine or biotechnology. The properties of aquaporins make them suitable for use as biomarkers of different aquaporin-related diseases when they are included in exosomes. Finally, the fact that these proteins could be immersed in biomimetic membranes opens future perspectives for new biotechnological applications.

Membrane Transporters in Citrus clementina Fruit Juice-Derived Nanovesicles

“…Aquaporins by regulating the flux of water and other small solute molecules across membranes are not only important for plant physiology but also for the interaction between plants and the environment. Vesicles containing aquaporin have recently come into the focus of EV research [18]. Here, the first time we demonstrate that vesicles of clementina contain tip (tonoplast intrinsic protein) and pip (plasma membrane intrinsic proteins) types of aquaporins.…”

“…Many integral MPs are transmembrane proteins (TM), which span the lipid bilayer with portions exposed on both sides of the membrane. The presence of tetraspanins [17], and aquaporins [18] MPs has been described in the various vesicle types. In our dataset, we have found 162 proteins associated with transport Gene Ontology (GO) term GO: 0006810 (Table S3) which includes 71 transmembrane transporters, 53 vesicle mediated transporters and 50 intracellular transporters (Figure 2A).…”

A Survey of Barley PIP Aquaporin Ionic Conductance Reveals Ca2+-Sensitive HvPIP2;8 Na+ and K+ Conductance

“…This could have physiological relevance in relation to regulating monovalent ion transport in conditions where K + is abundant relative to when Na + is in excess, such as in saline conditions. Water and ion transport are involved in the regulation of cell expansion, and aquaporins that can transport both ions and water could also potentially have key functions in cell expansion processes [ 55 , 56 ]. To understand the physiological roles of HvPIP2;8 , it will be necessary to phenotype the barley control and mutant or transgenic lines that significantly vary in the abundance of HvPIP2;8 .…”

Emerging roles for AQP in mammalian extracellular vesicles

“…Understanding active components of EV will advance this area further, allowing exogenous synthesis of EV, reducing the need for host organisms. As EV membrane composition is important for the successful delivery of EV in plants [23] we hypothesise AQP would be essential components of synthesised EV membranes.…”

“…AQP4 is associated with the development and resolution of brain oedema following injury and stroke [20] , [21] Alternative roles for AQPs have also been suggested due to their association with conditions apparently unrelated to water transport; AQP negative cancer cells have decreased motility, suggesting a role for AQPs in cell migration [22] . AQPs also contribute to cell membrane integrity [23] and cell communication [24] .…”