Additional file 1 of Phosphatidylinositol transfer protein-1 integrates insulin/IGF-1 and TOR signaling to negatively regulate lifespan and healthspan in Caenorhabditis elegans

Supplementary material 1. Supplementary Fig. 1. The reduction of class II PITP, pitp-1, reveals longevity-related phenotypes. (A) Schematic diagram of the pitp-1 genomic locus and mutant alleles. The pitp-1(pe1297) allele carries an approximately 2.95 kb genomic deletion replaced by a ~ 2.2 kb C. briggsae unc-119( +) cassette, and has been described as a candidate null allele. The pitp-1(tm1500) allele contains a deletion spanning coding regions and is predicted to cause a frameshift and premature truncation. (B) Schematic representation of the PITP-1 protein domain structure and predicted effects of the pitp-1 mutant alleles. PITP-1 contains an N-terminal PITP domain, followed by DDHD and LNS2 domains. The pitp-1(pe1297) allele is predicted to result in near-complete loss of the PITP domain (candidate null allele), whereas pitp-1(tm1500) is predicted to produce a truncated protein retaining only the N-terminal PITP domain. (C) Knockdown of pitp-1, but not other class I PITP homologs, extended lifespan in N2. (D-F) qPCR confirmed RNAi targeting class I PITP homologs specifically reduced their own transcript levels without affecting pitp-1. (G) pitp-1 mutants exhibited reduced body size. Each data point represents an individual animal. Data are presented as mean ± SD (n = 3 independent experiments). (H) Schematic diagram of RNAi treatment timelines. (I) pitp-1 knockdown during the reproductive stage promotes longevity. Survival curves are representative of three independent biological replicates. Data are presented as mean ± SD (n = 3 independent experiments) for quantitative analyses. Statistical significance was determined by log-rank test for lifespan assays, ANOVA for multiple comparisons.