A UBIQUITOUS PLATFORM FOR BACTERIAL NANOTUBE BIOGENESIS

Saurabh Bhattacharya ¹ Amit Baidya ¹ Ritesh Pal ¹ Gideon Mamou ^1,2 Yair Gatt ¹ Hanah Margalit ¹ Ilan Rosenshine ¹ Sigal Ben-Yehuda ¹

¹Department of Microbiology and Molecular Genetics, The Hebrew University of Jerusalem, Jerusalem, Israel
²Department of Biochemistry, University of Oxford, Oxford, UK

We previously described the existence of membranous nanotubes, bridging adjacent bacterial cells, facilitating intercellular trafficking of cytoplasmic molecules including nutrients, proteins, and even plasmids. We now reveal the identity of a molecular apparatus, providing a platform for nanotube biogenesis. Utilizing Bacillus subtilis, we demonstrate that highly conserved components of the flagellar export apparatus (FliO,P,Q,R, FlhB,A), herein termed CORE, dually serve for flagellar and nanotube assembly. Mutants lacking CORE genes, but not other essential flagellar components, were deficient in both nanotube production and intercellular molecular trade. Moreover, CORE components were located to sites of nanotube emergence, signifying their direct role in nanotube production. We further identified YmdB to colocalize with CORE, promoting nanotube formation. Deletion of CORE genes in distinct species along with a bioinformatics survey, substantiate the CORE as a common platform for nanotube generation by species belonging to diverse phyla, inferring that CORE-dependent molecular trafficking among bacteria could be immense.