The retromer complex is an evolutionarily conserved protein complex, studied extensively in yeast and mammalian systems. Mammalian retromer comprises a core complex of three subunits (VPS26, VPS29 and VPS35) bound to various sorting nexin (SNX) proteins. Although the role of retromer in endosomal trafficking is well-described, recent studies indicate additional roles for retromer in other cell trafficking events, as well as in apoptosis and regulation of centrosome duplication, among others. Other developmental roles of retromer in C. elegans have also been reported. In this study (Xie et al., 2022), the authors investigate the role of C. elegans VPS-26 (homologous to mammalian VPS26) during development and characterise new roles for retromer in ciliogenesis regulation in mammalian cells. First, the authors used CRISPR-Cas9 to knockout VPS-26 in C. elegans. Knockout worms had defective vulval development and a decreased body length compared to what is seen in wild-type worms. Although this could be indicative of potential ciliogenesis defects, this was challenging to investigate owing to the small size and low brood numbers of the animals. Thus, the authors depleted mammalian RPE-1 cells of all three retromer core complex subunits and various SNX proteins, and consistently observed decreased ciliogenesis. Importantly, the authors also characterised a novel role for retromer in the removal of CP110 from the mother centriole. Thus, retromer plays a newly described role in C. elegans development and regulation of ciliogenesis in mammalian cells.
