A role for post-transcriptional control of ER dynamics and function in C. elegans germline stem cell maintenance

Abstract

Membrane-bound receptors, crucial for mediating several developmental signals, are synthesized on endoplasmic reticulum (ER). Therefore, the functional integrity of ER must be important for the regulation of at least some of the developmental programs. However, the developmental control of ER function has not been well understood. Here, we identify the C. elegans protein FARL-11, an ortholog of the mammalian STRIPAK complex component STRIP1/2 (FAM40A/B), as an ER protein. In the embryo, we find that FARL-11 is essential for the cell cycle-dependent morphological changes of ER and embryonic viability. In the germline, FARL-11 is required for normal ER morphology and for the membrane localization of the GLP-1 / Notch receptor involved in germline stem cell (GSC) maintenance. Furthermore, we provide evidence that PUF-8, a key translational regulator in the germline, promotes the translation of farl-11 mRNA. These findings, thus, reveal that the ER form and function in the C. elegans germline are post-transcriptionally regulated and essential for the niche-GSC signaling mediated by GLP-1.