Post-translational modification acts as a digital like switch influencing AtPIP2;1 water and cation permeability.

Plant aquaporins (AQPs) were initially described as a family of membrane-localized proteins exclusively facilitating water transport. Subsequently, sub-sets of plant AQPs have exhibited diverse functionalities beyond water transport. The aquaporin AtPIP2;1, an abundant Plasma membrane Intrinsic Protein in Arabidopsis thaliana, can transport water but also CO, HO and monovalent cations under certain conditions.

Exploring aquaporin functions during changes in leaf water potential.

Maintenance of optimal leaf tissue humidity is important for plant productivity and food security. Leaf humidity is influenced by soil and atmospheric water availability, by transpiration and by the coordination of water flux across cell membranes throughout the plant. Flux of water and solutes across plant cell membranes is influenced by the function of aquaporin proteins.

A high-throughput yeast approach to characterize aquaporin permeabilities: Profiling the Arabidopsis PIP aquaporin sub-family.

Introduction: Engineering membrane transporters to achieve desired functionality is reliant on availability of experimental data informing structure-function relationships and intelligent design. Plant aquaporin (AQP) isoforms are capable of transporting diverse substrates such as signaling molecules, nutrients, metalloids, and gases, as well as water. AQPs can act as multifunctional channels and their transport function is reliant on many factors, with few studies having assessed transport function of specific isoforms for multiple substrates.

Molecular membrane separation: plants inspire new technologies.

Plants draw up their surrounding soil solution to gain water and nutrients required for growth, development and reproduction. Obtaining adequate water and nutrients involves taking up both desired and undesired elements from the soil solution and separating resources from waste. Desirable and undesirable elements in the soil solution can share similar chemical properties, such as size and charge.

Expression of a CO-permeable aquaporin enhances mesophyll conductance in the C species .

A fundamental limitation of photosynthetic carbon fixation is the availability of CO. In C plants, primary carboxylation occurs in mesophyll cytosol, and little is known about the role of CO diffusion in facilitating C photosynthesis. We have examined the expression, localization, and functional role of selected plasma membrane intrinsic aquaporins (PIPs) from (foxtail millet) and discovered that SiPIP2;7 is CO-permeable.

An algal PIP-like aquaporin facilitates water transport and ionic conductance.

Aquaporins are water and solute channel proteins found throughout the kingdoms of life. Ion-conducting aquaporins (icAQPs) have been identified in both plants and animals indicating that this function may be conserved through evolution. In higher plants icAQP function has been demonstrated for isoforms from two of five aquaporin subfamilies indicating that this function could have existed before the divergence of higher plants from green algae.

A Survey of Barley PIP Aquaporin Ionic Conductance Reveals Ca-Sensitive Na and K Conductance.

Some plasma membrane intrinsic protein (PIP) aquaporins can facilitate ion transport. Here we report that one of the 12 barley PIPs (PIP1 and PIP2) tested, , facilitated cation transport when expressed in oocytes. -associated ion currents were detected with Na and K, but not Cs, Rb, or Li, and was inhibited by Ba, Ca, and Cd and to a lesser extent Mg, which also interacted with Ca.

Phosphorylation influences water and ion channel function of AtPIP2;1.

The phosphorylation state of two serine residues within the C-terminal domain of AtPIP2;1 (S280, S283) regulates its plasma membrane localization in response to salt and osmotic stress. Here, we investigated whether the phosphorylation state of S280 and S283 also influence AtPIP2;1 facilitated water and cation transport. A series of single and double S280 and S283 phosphomimic and phosphonull AtPIP2;1 mutants were tested in heterologous systems.

Deciphering aquaporin regulation and roles in seed biology.

Seeds are the typical dispersal and propagation units of angiosperms and gymnosperms. Water movement into and out of seeds plays a crucial role from the point of fertilization through to imbibition and seed germination. A class of membrane intrinsic proteins called aquaporins (AQPs) assist with the movement of water and other solutes within seeds.

Divalent Cations Regulate the Ion Conductance Properties of Diverse Classes of Aquaporins.

Aquaporins (AQPs) are known to facilitate water and solute fluxes across barrier membranes. An increasing number of AQPs are being found to serve as ion channels. Ion and water permeability of selected plant and animal AQPs (plant AtPIP2;1, AtPIP2;2, AtPIP2;7, human HsAQP1, rat RnAQP4, RnAQP5, and fly DmBIB) were expressed in oocytes and examined in chelator-buffered salines to evaluate the effects of divalent cations (Ca, Mg, Ba and Cd) on ionic conductances.

Roles of Aquaporins in Stem Development and Sugar Storage.

is a C grass used as a model for bioenergy feedstocks. The elongating internodes in developing stems grow from an intercalary meristem at the base, and progress acropetally toward fully expanded cells that store sugar. During stem development and maturation, water flow is a driver of cell expansion and sugar delivery.