ER structure and functionality are influenced by temperature and heat stress. This also affects the structure and organization of the ER-nuclear interface, which impairs protein transport to the nucleus. In this project we address the hypothesis that under heat stress, ER shaping proteins modify properties of the nuclear envelope (NE) resulting in changes in membrane tension and with this in structural changes of Nuclear Pore Complexes (NPC). Therefore, we will analyse heat-stress induced changes in ER-NE interface structures labelled by ER lumenal and membrane markers tagged to fluorescent proteins (GFP-HDEL, calnexin-GFP) using our specialized software AnalyzER measuring over 250 structural and dynamics ER parameters (e.g. cisternae area, tubule length, persistency) on high-resolution confocal (AiryScan/NSPARC detectors).