Subcellular localisation of mRNAs contributes to the generation and maintenance of cellular asymmetry, embryonic development and neuronal function. In Saccharomyces cerevisiae, several bud-localised mRNAs encode membrane proteins that are translated at the cytoplasmic face of the endoplasmic reticulum (ER), but there is still much to be learned about the factors involved in the localisation of membrane-protein-encoding mRNAs. Here (p. 3373), Ralf-Peter Jansen and colleagues aim to identify novel factors required for ER-dependent mRNA localisation to the yeast bud in order to gain more insight into the mechanism and determinants of this type of mRNA localisation. The authors performed a visual screen of ER mutant strains for ER-specific proteins required for the directional transport of two early expressed mRNAs, WSC2 and EAR1, and identified 13 novel genes, many of which encode ER proteins that are involved in phospholipid metabolism. One of these mutants lacked the phosphatidylethanolamine (PtdEtn) N-methyltransferase Cho2p, a key enzyme in phosphatidylcholine (PtdCho) biosynthesis. A careful analysis of the phenotype of a mutant lacking Cho2p showed that an imbalance in the PtdEtn:PtdCho levels caused a malformed cortical ER network and the mislocalisation of WSC2 and EAR1. These results provide, for the first time, evidence of a functional relevance of specific lipids in the co-trafficking of mRNAs and ER.