%0 Generic
%A Platzek, Anna
%C Heidelberg
%D 2025
%F heidok:36746
%R 10.11588/heidok.00036746
%T Organellar remodeling during stress in Saccharomyces cerevisiae
%U https://archiv.ub.uni-heidelberg.de/volltextserver/36746/
%X Cells have to adapt rapidly to changing physiological demands, such as differentiation, stress  and disease. Extensive studies have defined many stress response pathways at the level of  gene activity and protein abundance, but stress-induced changes of protein subcellular  localization have not been investigated comprehensively on a proteome-wide level.  In this thesis, I established and applied the Dynamic Organellar Maps (DOMs) approach by  label-free mass spectrometry for the first time to yeast. DOMs detected protein localization  changes of native, untagged proteins upon different stresses.  Firstly, I used endoplasmic reticulum (ER) stress and found that almost 10% of the known  proteins expressed in yeast, shifted within or between organelles. I showed that a distinct  multitude of secretory pathway proteins accumulated in the ER. In-depth analysis and  experimental validation refined the extent and selectivity of misfolded proteins retained in  the ER. Moreover, I identified new ER proteins subjected to the ER reflux pathway and  identified transmembrane components of reticulon clusters, which separated from the  residual ER. Lastly, I demonstrated that nuclear pore complex integrity was altered which  affected nuclear import.  Secondly, I applied DOMs to nitrogen-starved cells to identify novel cargo proteins which were  degraded by non-selective macroautophagy. I detected several proteins which were already  known to be autophagic cargos or to be involved in cargo recruitment and transport. Further  analysis provided a list of candidate cargo proteins which serve as a basis to determine if  starvation induced autophagy degrades cargo proteins non-selectively.  In conclusion, I established DOMs in yeast and revealed that global and suborganellar changes  in protein localization are key elements of cellular stress responses.