Artículos de revistas
Intracellular pH sensing is altered by plasma membrane PIP aquaporin co-expression
Fecha
2010-09Registro en:
Bellati, Jorge; Alleva, Karina Edith; Soto, Gabriela Cynthia; Vitali, Victoria Andrea; Jozefkowicz, Cintia; et al.; Intracellular pH sensing is altered by plasma membrane PIP aquaporin co-expression; Springer; Plant Molecular Biology; 74; 1; 9-2010; 105-118
0167-4412
1573-5028
Autor
Bellati, Jorge
Alleva, Karina Edith
Soto, Gabriela Cynthia
Vitali, Victoria Andrea
Jozefkowicz, Cintia
Amodeo, Gabriela
Resumen
The plant plasma membrane barrier can express aquaporins (PIP1 and PIP2) that show two intriguing aspects: (1) the potential of modulating whole membrane water permeability by co-expression of both types, which have recently been distinguished for showing a different capacity to reach the plasma membrane; and (2) the faculty to reduce water permeation through the pore after cytosolic acidification, as a consequence of a gating process. Our working hypothesis is that these two key features might enhance plasticity of the membrane water transport capacity if they jointly trigger any cooperative interaction. In previous work, we proved by biophysical approaches that the plasma membrane of the halophyte Beta vulgaris storage root presents highly permeable aquaporins that can be shut down by acidic pH. Root Beta vulgaris PIPs were therefore subcloned and expressed in Xenopus oocytes. Co-expression of BvPIP1;1 and BvPIP2;2 not only enhances oocyte plasma membrane water permeability synergistically but also reinforces pH inhibitory response from partial to complete shut down after cytosolic pH acidifi- cation. This pH dependent behavior shows that PIP1–PIP2 co-expression accounts for a different pH sensitivity in comparison with PIP2 expression. These results prove for the first time that PIP co-expression modulates the membrane water permeability through a pH regulatory response, enhancing in this way membrane versatility to adjust its water transfer capacity.