MECHANISMS UNDERLYING REPLICATIVE LIFESPAN EXTENTION IN YEAST

SALZMAN, VALENTINA; AGUILAR, PABLO S.

VIRTUAL

Congreso; LVII SAIB Annual Meeting - XVI SAMIGE Meeting (virtual); 2021

SAIB-SAMIGE

Eisosomes are plasma membrane (PM) domains concentratinglipids and proteins. In Saccharomyces cerevisiae, these domains are shaped as 200–400-nm long and 50-nm-deep invaginatedfurrows structured by scaffolds composed mainly by twocytoplasmic proteins Pil1 and Lsp1. Deletion of PIL1 leadsto disappearance of invaginations, very few and large clusters persist at the PM concentrating a fraction of the originaleisosomal proteins (eisosomes ́ remmants). We study eisosomes ́ rolein aging measuring the number of daughters produced by yeastmother cells of a dividing culture (replicative aging model, RLS). Performing RLS assays we found that knockout strainsfor PIL1 have significantly extended longevity. A decrease inthe concentration of glucose or certain amino acids in theculture medium extends RLS in S. cerevisiae. Eisosomes are storage compartments of many nutrients transporters and theimportance of proper eisosome organization for protein functionality has been demonstrated for arginine permease Can1. In addition,deletion of arginine or tryptophan eisosomal permease genes, CAN1 and TAT2, respectively, decreases amino acid cytosoliccontents and correlates with an extension in RLS. Based on this evidence, we propose that the absence of eisosomalorganization leads to a nutrient- imbalance state and/or alters nutrient signaling extending RLS. We found that the kinetics ofglucose consumption associated to eisosomes ́ disassembly is not significantly different from WT strain, suggesting that theextension of longevity in pil1 mutant is not given by a difference in glucose consumption. While the importance of proper domainassociation for protein functionality has been demonstrated for Can1, the role of eisosomes in Tat2 functionality and / oravailability was unknown. Measuring 3HTrp import in vivo we found that PIL1 deletion does not generate a decrease in Trpincorporation. Therefore, a deficiency in Tat2 activity does not seem to be underling the RLS extension mechanism in study. GeneralAminoacid Control/ Gcn4(ATF4)-depending pathway activity was determined performing reporter gene assays with lacZgene under the control of GCN4 3 ́UTR region in eisosomalmutants. In conjunction with cytosolic amino acidquantifications these experiments will enable us to determine whether anaminoacids imbalance state is underlying eisosome disassembly-dependent RLSextension. This study will provide a comprehensive resource for analyzing domain structurationrole in aging in yeast which should also be valuable for understanding similar phenomena in other organisms.@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-536859905 -1073732485 9 0 511 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}div.WordSection1{page:WordSection1;}