Researchers discover injection machines in bacteria

At the Swiss Federal Institute of Technology in Zurich (ETH), a previously unknown injection mechanism has now been discovered in two cell types. A team of researchers from the Institute of Molecular Biology and Biophysics at ETH Zurich headed up by Professor Martin Pilhofer described these two novel injection systems in studies published in the same issue of the journal “Nature Microbiology”.

According to a press release, these injection machines can be found in two types of cell: one in a blue-​green algae known as cyanobacteria and the other in the marine bacterium Algoriphagus machipongonensis. They work like molecular syringes: Upon contact with potential target cells, they fire their protein charge from a tube. Depending on the loading of these syringe systems, it can trigger the transformation of a larva, kill foreign strains of bacteria or defend against scavenger cells.

Moreover, the two molecular spearguns occur unexpectedly frequently. According to Gregor Weiss, lead author of the study on the cyanobacterial injection system, this indicates an important role in the life cycle of cyanobacteria. “The newly discovered nano machines give us clues that contractile injection systems are more common than previously thought”, explains Charles Ericson, who published the study into the marine bacterium together with a colleague.

According to ETH Zurich, it is conceivable that researchers will use its structure comprising several modules in the area of biomedicine in future. In fact, it could be redesigned so that “a molecular speargun could target specific cell types and fire drugs or antimicrobials”.