IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Flexible N and C terminal domains in aquaporin gating
Autor/es:
ZERBETTO DE PALMA, GERARDO; SOTO, GABRIELA; SCOCHERA, FLORENCIA; ZEIDA, ARI; TORIANO, ROXANA; ALLEVA, KARINA
Lugar:
San Luis
Reunión:
Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Biofísica; 2019
Institución organizadora:
Sociedad Argentina de Biofísica
Resumen:
Plant plasma membrane intrinsic proteins (PIP) have a very conserved 3D structure butmany questions remain open regarding the structure-function relationship involved ingating. These are tetrameric channels that are largely composed by transmembranealpha helices (approximately 60%) and flexible elements, such as loops and both, N andC termini (NT and CT). It is known that NT and CT can have important roles in channelfunctionality and some reports suggested that they may be involved in PIP gating. NTand CT are quite flexible elements and are not present in the available structures. PIPhave longer NT (30-46 residues) than CT (10-17 residues), being NT negatively chargedand CT positively charged. Despite these ends are the least conserved elements in PIPsubfamily, some residues are highly conserved: in particular a PPP motif in NT, Glu andAsp residues in NT1,2 and Ser and Arg residues in CT. Previous studies confirmed that NTacidic residues are important in PIP gating and controversial results were reported forCT?s serine3,4. In this work, we study the participation of both CT and NT in pH gating ofBeta vulgaris PIP. We constructed BvPIP mutants altering conserved residues, performedfunctional experiments and molecular dynamics simulations. Our results show that thePPP motif and R285 are involved in the PIP open-close transition triggered by cytosolicacidification, while S283 is not. These experimental and in silico approaches will let usunveil the role of NT and CT in PIP gating mechanism.