Fig. 4: FASN-CTF diminishes chronically elevated stress-responsive gene expression and metabolic programs.
From: Proteolytic activation of fatty acid synthase signals pan-stress resolution
a, Western blot showing in vivo stabilities of FASN-NTF and CTF. Auxin-controlled endogenous FASN-1 (FL) or a single-copy transgene expressing either NTF or CTF all contain an HA tag for detection. Western blot for stability of FASN fragments was repeated twice independently with similar results. b,c, HSP-4p::GFP expression (b) and quantification (c) under ER stress with expression of FASN-CTF or NTF in ced-3(-). n = 30 animals. d,e, HSP-4p::GFP induction under ER stress in ced-3(-) animals with expression of FASN-CTF only in muscle (d) or only in intestine (e). n = 30 animals (d,e). Scale bar, 200 μm (b,d,e). f, Growth rate of animals with and without expression of FASN-CTF. n = 5 biological replicates with total of n = 441 (−CTF) and n = 303 (+CTF) animals were assayed. Mean ± s.d. g,h, Impact of FASN-CTF on ced-3(-) mutant for alterations in gene expression under ER stress using the gene set analysis tool in WormBase (wormbase.org/tools/enrichment/tea/tea.cgi) (g) and WormCat (wormcat.com/) (h). Heat maps (g,h) show mRNA log2FC of ced-3(-) mutant expressing CTF compared to ced-3(-) with no CTF expression. n = 3 biological replicates. FDR < 0.1 and absolute value of log2FC > 1 were thresholds for enrichment analysis (g,h). i, NAC level in ced-3(-) with and without CTF expression. n = 5 biological replicates. Mean ± s.d. j, Impact of FASN-CTF expression on ced-3(-) mutant for selected metabolites under ER stress. Heat map shows log2FC of ced-3(-) mutant expressing CTF compared to ced-3(-) with no CTF expression. n = 5 biological replicates. FA, fatty acid; PC, phosphatidylcholine; PE, phosphatidylethanolamine; PI, phosphatidylinositol; PS, phosphatidylserine; Lyso-PC, lysophosphatidylcholine; Lyso-PE, lysophosphatidylethanolamine; TCA, tricarboxylic acid. P values were calculated using an unpaired two-tailed t-test (f,i), two-tailed Mann–Whitney U-test (c–e) or one-tailed Fisher’s exact test (h).
