Fig. 1: Loss of Paip1 causes lethality and reduces translation.

A Generation of mutation in Drosophila Paip1. Diagrams showing the genomic region around the Paip1 locus, the target sequence of sgRNA, and the DNA/RNA/protein after Cas9/sgRNA induced mutation. Paip1 mutant allele contains 1-bp deletion around the target region, which induces a codon shift and generates a truncated protein due to premature translation termination. B Images of pupae and adult flies with the indicated genotype. Wild-type and Paip1 mutant pupae and adult flies were collected 5 days after egg hatching and 10 days after egg hatching. Scale bars, 500 µm. C Western blot of wild-type and Paip1 mutant larvae extracts probed with anti-Paip1 and anti-Actin antibodies. The anti-Paip1 antibody detects a single 65 KD band in wild-type larvae, which was absent in Paip1 mutants. D Quantification of rescue of lethality in various genotypes. Flies with the indicated genotypes were crossed. The number of progenies with the indicated genotypes was counted. A Paip1-20K transgene fly carries a 20-kb duplicated genomic fragment containing the entire Paip1 gene region (CH322-46004). Introducing one copy of Paip1-20 K transgene into the Paip1 mutant background was able to rescue the lethality defect. E Polysome profiles from wild-type and Paip1 mutant larvae. Monosome fraction and Polysome fraction were collected for Polysome sequencing. F Scatter plot of TE log2 fold-changes to total mRNA log2 fold-changes in wild-type and Paip1 mutant larvae with RNA-seq. The number of mRNAs with a change in TE (blue and red) are indicated (|RNA-seq log2FC| < 1 and |TE log2FC| > 1). TE, translational efficiency. Each dataset includes 2 replicates. G GO enrichment analysis of TE-Down genes and TE-Up genes. H Western blot of w¹¹¹⁸ and Paip1 mutant larvae extracts probed with anti-RPL40, anti-RPS6, and anti-Tubulin antibodies.