show Abstracthide AbstractCRISPRi screens on the repression of 129 protein kinases and 161 transcription factors in S. cerevisiae. We quantify perturbation effects on cellular fitness at 23, 30 and 38°C, expression of the SSA1 Hsp70 chaperone (as proxy for heat shock response activity) and thermotolerance. The integration of these phenotypes allowed us to identify core signaling pathways of the HSR and their contributions to temperature-associated growth and heat resistance. Overall design: CRISPR interference screens in S. cerevisiae in bulk yeast populations on five selection conditions: competitive growth assays over 1.5-2 days at temperatures 23, 30 and 38°C, survival of a lethal heat shock (150 min at 50°C, including recovery without maintaining CRISPRi induction), and chaperone expression as a proxy for heat shock response activity (FACS-based collection of cells by their cellular Hsp70 GFP reporter intensity).