Localized translation oferm-1contributes to ERM-1 function in theC. elegansembryo

Summary Translation of mRNAs into proteins is a key step in decoding the information stored in the genome. Localized translation ensures that proteins are expressed where needed, which is important for cell-specific protein expression, the establishment of cellular protein gradients, and the creation of protein hotspots within different cellular compartments. Although localized translation is believed to be important for cell fate determination and organismal development, our understanding of localized translation in the context of living animals is limited, as few methods that allow direct visualization and measurement of translation exist. We adapted the SunTag-based single-molecule translation imaging system for use in Caenorhabditis elegans and showed the dynamics and importance of localized erm-1 translation during development. We found erm-1 translation to be enriched at the plasma membrane, overlapping with the localization and function of the encoded membrane-cytoskeleton linker ERM-1. Re-localizing erm-1 translation to nuclear pores disrupts the function of ERM-1 protein, particularly its role in linking the actin cytoskeleton to the membrane. Our work demonstrates the power of translation imaging and highlights the importance of localized translation in C. elegans development.