Translation of the ERM-1 membrane-binding domain directserm-1mRNA localization to the plasma membrane in theC. elegansembryo

ABSTRACT mRNA localization and transport are integral in regulating gene expression. In Caenorhabditis elegans embryos, the maternally inherited mRNA erm-1 (Ezrin/Radixin/Moesin) concentrates in anterior blastomeres. erm-1 mRNA localizes within those blastomeres to the plasma membrane where the essential ERM-1 protein, a membrane-actin linker, is also found. We demonstrate that the localization of erm-1 mRNA to the plasma membrane is translation-dependent and requires its encoded N-terminal membrane-binding (FERM) domain. By perturbing translation through multiple methods, we found erm-1 mRNA localization at the plasma membrane was maintained only if the nascent peptide remained in complex with the translating mRNA. Indeed, recoding the erm-1 mRNA coding sequence while preserving the encoded amino acid sequence did not disrupt erm-1 mRNA localization, corroborating that the information directing mRNA localization resides within its membrane-binding protein domain. A smiFISH screen of 17 genes encoding similar membrane-binding domains identified three plasma membrane localized mRNAs in the early embryo. Nine additional transcripts showed apparent membrane localization later in development. These findings point to a translation-dependent pathway for localization of mRNAs encoding membrane-associated proteins. SUMMARY STATEMENT In C. elegans, erm-1 mRNA localization to plasma membranes requires translation of the ERM-1 membrane-binding domain