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Progeria syndromes are very rare, incurable premature aging conditions recapitulating most aging features. Here, we report the first whole genome, multiparametric CRISPR anti-aging screen, identifying 43 new genes that can reverse multiple aging phenotypes in progeria. The screen was implemented in fibroblasts from Néstor- Guillermo Progeria Syndrome (NGPS) patients, carrying a homozygous p.Ala12Thr mutation in barrier-to-autointegration factor (BAF A12T). The hits were enriched for genes involved in protein translation, protein and RNA transport and osteoclast formation. We further confirmed that BAF A12T drives increased protein translation and translational errors that could directly contribute to premature aging in patients. This work has highlighted the power of multiparametric whole genome synthetic rescue screens to identify new anti-aging genes and uncover novel biology behind progeria-associated cellular dysfunction.One-Sentence SummaryA whole genome multiparametric screen in progeria identifies new pathways that can reverse cellular aging phenotypes.

Summary Background In nematodes, plants, and fungi, RNAi is remarkably potent and persistent due to the amplification of initial silencing signals by RNA-dependent RNA polymerases (RdRPs). In Caenorhabditis elegans ( C. elegans ), the interaction between the RNA-induced silencing complex (RISC) loaded with primary small interfering RNAs (siRNAs) and the target messenger RNA (mRNA) leads to the recruitment of RdRPs and synthesis of secondary siRNAs using the target mRNA as the template. The mechanism and genetic requirements for secondary siRNA accumulation are not well understood. Results From a forward genetic screen for C. elegans genes required for RNAi, we identified rde-10 , and through proteomic analysis of RDE-10-interacting proteins, we identified a protein complex containing the new RNAi factor RDE-11, the known RNAi factors RSD-2 and ERGO-1, and other candidate RNAi factors. The RNAi defective genes rde-10 and rde-11 encode a novel protein and a RING-type zinc finger domain protein, respectively. Mutations in rde-10 and rde-11 genes cause dosage-sensitive RNAi deficiencies: these mutants are resistant to low dosage but sensitive to high dosage of double-stranded RNAs. We assessed the roles of rde-10 , rde-11 , and other dosage-sensitive RNAi-defective genes rsd-2 , rsd-6 , and haf-6 in both exogenous and endogenous small RNA pathways using high-throughput sequencing and qRT-PCR. These genes are required for the accumulation of secondary siRNAs in both exogenous and endogenous RNAi pathways. Conclusions The RDE-10/RDE-11 complex is essential for the amplification of RNAi in C. elegans by promoting secondary siRNA accumulation.

During sporulation and meiosis of budding yeast a developmental program determines the formation of the new plasma membranes of the spores. This process of prospore membrane (PSM) formation leads to the formation of meiotic daughter cells, the spores, within the lumen of the mother cell. It is initiated at the spindle pole bodies during meiosis II. Spore formation, but not meiotic cell cycle progression, requires the function of phospholipase D (PLD/Spo14). Here we show that PLD/Spo14 forms a complex with Sma1, a meiotically expressed protein essential for spore formation. Detailed analysis revealed that both proteins are required for early steps of prospore membrane assembly but with distinct defects in the respective mutants. In the Deltaspo14 mutant the initiation of PSM formation is blocked and aggregated vesicles of homogenous size are detected at the spindle pole bodies. In contrast, initiation of PSM formation does occur in the Deltasma1 mutant, but the enlargement of the membrane is impaired. During PSM growth both Spo14 and Sma1 localize to the membrane, and localization of Spo14 is independent of Sma1. Biochemical analysis revealed that Sma1 is not necessary for PLD activity per se and that PLD present in a complex with Sma1 is highly active. Together, our results suggest that yeast PLD is involved in two distinct but essential steps during the regulated vesicle fusion necessary for the assembly of the membranous encapsulations of the spores.

Chromosome segregation during mitosis and meiosis depends on the linkage of sister DNA molecules after replication. These links, known as sister-chromatid cohesion, are provided by a multi-subunit complex called cohesin. Recent papers suggest that chromatin-remodeling complexes also have a role in the generation of sister-chromatid cohesion. It remains unclear whether they do so by facilitating the recruitment of cohesin to specific chromosomal sequences or by modifying an event at replication forks giving rise to cohesion between sister DNAs.