STUDYING THE ROLE OF EISOSOMAL MEMBRANE DOMAINS IN CELLULAR AGING

SALZMAN, VALENTINA; NIEVAS, MICAELA; PATERNOSTE, MARIBEL; CORREA TEDESCO, FRANCISCO; AGUILAR, PABLO S

Parana

Congreso; LIV SAIB Annual Meeting; 2018

SAIB

The plasma membrane (PM) of eukaryotic cells is compartmentalized into domains enriched in specific lipids and proteins. Saccharomycescerevisiae contains at least a dozen of different nanodomains that exhibit different morphologies and dynamic behaviors. Particularly, eisosomesare nanoscale PM invaginations structured by scaffolds composed mainly by two cytoplasmic proteins Pil1 and Lsp1. More than 25 proteinsincluding transporters, signaling molecules and proteins of unknown function have been localized in eisosomes, however, much remains to belearned about the mechanisms and biological roles of this lateral segregation. We are interested in understanding eisosomes´ role in agingusing S. cerevisiae aging model. Performing replicative yeast aging assays we found that knockout strains for PIL1 (eisosomes´ dissasembled)have significantly enhanced longevity. No effect was observed when LSP1 was deleted (eisosomes assembled), suggesting that eisosomes´structure plays a key role in yeast aging. Chronological aging assays were performed using the standard CFU method and propidium iodide cellstainingfollowed by flow cytometry to determine cell survival in two different genetic backgrounds. In order to determine if the longevityof PIL1 mutant is associated with a limitation in the availability of nutrients, an uptake assay was set up enabling the challenge of a specifichypothesis: activity of an aminoacideisosomal permease is affected by eisosomes´ disassembly increasing lifespan. Understanding eisosomes´role in aging will likely contribute to further describing complex S. cerevisiae aging process and nanoscale PM domains function.