Heterologous Membrane Proteins Co-Trigger E. coli Filamentation, Polyploidy, and Membrane Remodeling to Boost...

In biosynthesis, while focusing on the productivity of individual compounds, the development of high-efficiency bio-components and universal enabling tools for advancing biosynthesis remains a critical and persistent challenge. Plant-derived Integral Membrane Proteins (IMPs) from two distinct families were heterologously expressed in E. coli, inducing filamentous cell growth, increased membrane permeability, polyploidy, and growth arrest. GFP-tagged IMPs were successfully delivered to the cell membrane. Filamentous cells contained significantly elevated DNA content, and displayed a rough surface morphology, an enlarged periplasmic space, and heightened sensitivity against membrane and cell wall stressors. These findings correspond to significantly altered transcription of genes linked to cell membrane and wall integrity, including those regulating cell division, elongation, DNA replication, and IMP delivery. Notably, the observed cellular toxicity could be modulated by chimeric fusion of the N-terminus and a certain number of hydrophobic transmembrane helices, potentially through α-aggregation-mediated membrane disruption. Finally, we demonstrated that IMP expression enhanced biosynthesis in all six tested scenarios, including biocatalysis, fermentation, and mixed-cell catalysis for the production of diverse chemicals. A plant-IMPs toolkit has been developed for versatile biosynthetic applications in E. coli.