CHARACTERIZATION OF THE ALTERNATIVE SPLICING VARIANT OF THE PIP SUBFAMILY IN Medica- go Truncatula: THE TRUNCATED PROTEINS VARIANTS AS NEW ELEMENTS OF HETERO-OLIGOMERIZATION REGULATION

VICTORIA VITALI; CINTIA JOZEFKOWICZ; ROMINA FRARE; EZEQUIEL PETRILLO; GERD PATRICK BIENERT; NICOLAS AYUB; GABRIELA SOTO; KARINA ALLEVA

CABA

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

PIPs are transmembrane proteins of great biological importance given the large number of representatives found in plants and the specific ability to transport different small compounds (water, CO​2,​ H​2O​ ​2,​ ions). The functional diversity and localization of this protein family is usually attributed to three possible mechanisms: a) transcriptional regulation and mRNA processing; B) interaction of different monomers forming hetero-oligomers and c) the presence of regulatory subunits coupled to the structure of the transmembrane proteins. To date, in this family, important advances have been made in understanding the post-translational regulation mechanisms such as hetero-oligomerization and gating by pH, calcium, and / or phosphorylation. In contrast, the mechanisms of transcriptional regulation and RNA processing have not yet been addressed in depth. In the field of biology, co-transcriptional modifications occurring on mRNAs by splicing and alternative splicing are crucial in the protein diversity present in eukaryotic organisms. Our preliminary results in ​Medicago truncatula suggest that splicing variants would determine the translation of truncated protein variants. Unlike prior reports for other plant Membrane Intrinsic Proteins (MIPs), these protein variants lack two complete transmembrane helix and one extracellular loop. The existence of these variants opens new questions about the role they could play in PIP regulation in particular but in​ ​plant​ ​metabolism​ ​in​ ​general.