The extracellular contractile injection systems(e CISs)are encoded in the genomes of a large number of bacteria and archaea.We have previously characterized the overall structure of Photorhabdus Virulence Cassette(PVC...The extracellular contractile injection systems(e CISs)are encoded in the genomes of a large number of bacteria and archaea.We have previously characterized the overall structure of Photorhabdus Virulence Cassette(PVC),a typical member of the e CIS family.PVC resembles the contractile tail of bacteriophages and exerts its action by the contraction of outer sheath and injection of inner tube plus central spike.Nevertheless,the biological function of PVC effectors and the mechanism of effector translocation are still lacking.By combining cryo-electron microscopy and functional experiments,here we show that the PVC effectors Pdp1(a new family of widespread d NTP pyrophosphatase effector in e CIS)and Pnf(a deamidase effector)are loaded inside the inner tube lumen in a"Peas in the Pod"mode.Moreover,we observe that Pdp1 and Pnf can be directly injected into J774 A.1 murine macrophage and kill the target cells by disrupting the d NTP pools and actin cytoskeleton formation,respectively.Our results provide direct evidence of how PVC cargoes are loaded and delivered directly into mammalian macrophages.展开更多
基金supported by the National Natural Science Foundation of China(31870108,32070081,32000080,31725007,31630087,and 31922036)the Beijing Natural Science Foundation(5192019)+3 种基金the CAMS Innovation Fund for Medical Sciences(2016-I2M-1013)the Non-profit Central Institute Fund of Chinese Academy of Medical Sciences(2017PT31049,2018PT51009,and 2018PT31012)the National Key Research and Development Program of China(2019YFA0508904)supported by High-performance Computing Platform of Peking University。
文摘The extracellular contractile injection systems(e CISs)are encoded in the genomes of a large number of bacteria and archaea.We have previously characterized the overall structure of Photorhabdus Virulence Cassette(PVC),a typical member of the e CIS family.PVC resembles the contractile tail of bacteriophages and exerts its action by the contraction of outer sheath and injection of inner tube plus central spike.Nevertheless,the biological function of PVC effectors and the mechanism of effector translocation are still lacking.By combining cryo-electron microscopy and functional experiments,here we show that the PVC effectors Pdp1(a new family of widespread d NTP pyrophosphatase effector in e CIS)and Pnf(a deamidase effector)are loaded inside the inner tube lumen in a"Peas in the Pod"mode.Moreover,we observe that Pdp1 and Pnf can be directly injected into J774 A.1 murine macrophage and kill the target cells by disrupting the d NTP pools and actin cytoskeleton formation,respectively.Our results provide direct evidence of how PVC cargoes are loaded and delivered directly into mammalian macrophages.
