Fig. 6

PLS3 overexpression and sym-2(RNAi) suppress endocytic defects caused by smn-1(RNAi) knockdown and summary. a Pie charts illustrating the percentage of animals with the indicated accumulation of GFP in the body cavity. Soluble GFP is secreted from the muscle cells into the body cavity. Coelomocyte-specific knockdown of smn-1 leads to GFP accumulation in the body cavity due to endocytic pathway defects. Either coelomocyte-specific expression of PLS3 or coelomocyte-specific knockdown of sym-2 suppressed GFP accumulation, consistent with cell-autonomous action of these proteins in coelomocytes. n > 40 animals pooled from multiple extrachromosomal array lines, combined from 3 independent trials. Scorers were blinded to the genotype of animals for each trial. Statistics calculated using chi-square. b Representative images for “no body GFP,” “some body GFP,” and “strong body GFP.” c Based on results presented here and previous work, a summary of functional genetic interactions is shown. c Normal levels of SMN protein facilitate appropriate transport and translation of “endocytic mRNAs,” which encode proteins involved in endocytosis. As an actin-bundling protein, PLS3 may contribute to transport or localization of RNP granules (gray circles) that contain “endocytic mRNAs,” as well as SMN, hnRNPF/H, and other proteins. d When SMN levels drop, the number, trafficking, or function of RNP granules containing “endocytic mRNAs” is perturbed, resulting in fewer endocytic proteins and endocytic defects. e The deleterious consequences of decreased SMN levels can be ameliorated by increasing PLS3 levels or by decreasing hnRNP F/H levels. The illustration of SMN and hnRNP F/H in an RNP tethered by PLS3 is speculative, but increasing PLS3 or decreasing hnRNPF/H ortholog activity ameliorates both functional defects and endocytic defects in the C. elegans model