Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, POB 12272, 91120, Jerusalem, Israel.
Nat Commun. 2020 Apr 22;11(1):1938. doi: 10.1038/s41467-020-15605-1.
Bacteria can produce membranous nanotubes that mediate contact-dependent exchange of molecules among bacterial cells. However, it is unclear how nanotubes cross the cell wall to emerge from the donor or to penetrate into the recipient cell. Here, we report that Bacillus subtilis utilizes cell wall remodeling enzymes, the LytC amidase and its enhancer LytB, for efficient nanotube extrusion and penetration. Nanotube production is reduced in a lytBC mutant, and the few nanotubes formed appear deficient in penetrating into target cells. Donor-derived LytB molecules localize along nanotubes and on the surface of nanotube-connected neighbouring cells, primarily at sites of nanotube penetration. Furthermore, LytB from donor B. subtilis can activate LytC of recipient bacteria from diverse species, facilitating cell wall hydrolysis to establish nanotube connection. Our data provide a mechanistic view of how intercellular connecting devices can be formed among neighbouring bacteria.
细菌可以产生膜状纳米管，介导细菌细胞之间依赖接触的分子交换。然而，纳米管如何穿过细胞壁从供体中伸出或穿透进入受体细胞尚不清楚。在这里，我们报告枯草芽孢杆菌利用细胞壁重塑酶，即 LytC 酰胺酶及其增强子 LytB，实现高效的纳米管挤出和穿透。在 lytBC 突变体中，纳米管的产生减少，并且形成的少数纳米管似乎缺乏穿透进入靶细胞的能力。供体来源的 LytB 分子沿着纳米管和连接到纳米管的相邻细胞的表面定位，主要位于纳米管穿透的部位。此外，来自供体枯草芽孢杆菌的 LytB 可以激活来自不同物种的受体细菌的 LytC，促进细胞壁水解以建立纳米管连接。我们的数据提供了一种机制性的观点，即相邻细菌之间如何形成细胞间连接装置。
