Cytoplasmic contractile injection systems mediate cell death in Streptomyces
Contractile injection systems (CIS) are bacteriophage tail-like structures that mediate bacterial cell–cell interactions. While CIS are highly abundant across diverse bacterial phyla, representative gene clusters in Gram-positive organisms remain poorly studied. Here we characterize a CIS in the Gra...
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Published in | Nature microbiology Vol. 8; no. 4; pp. 711 - 726 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
01.04.2023
Nature Publishing Group |
Subjects | |
Online Access | Get full text |
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Summary: | Contractile injection systems (CIS) are bacteriophage tail-like structures that mediate bacterial cell–cell interactions. While CIS are highly abundant across diverse bacterial phyla, representative gene clusters in Gram-positive organisms remain poorly studied. Here we characterize a CIS in the Gram-positive multicellular model organism
Streptomyces coelicolor
and show that, in contrast to most other CIS,
S. coelicolor
CIS (CIS
Sc
) mediate cell death in response to stress and impact cellular development. CIS
Sc
are expressed in the cytoplasm of vegetative hyphae and are not released into the medium. Our cryo-electron microscopy structure enabled the engineering of non-contractile and fluorescently tagged CIS
Sc
assemblies. Cryo-electron tomography showed that CIS
Sc
contraction is linked to reduced cellular integrity. Fluorescence light microscopy furthermore revealed that functional CIS
Sc
mediate cell death upon encountering different types of stress. The absence of functional CIS
Sc
had an impact on hyphal differentiation and secondary metabolite production. Finally, we identified three putative effector proteins, which when absent, phenocopied other CIS
Sc
mutants. Our results provide new functional insights into CIS in Gram-positive organisms and a framework for studying novel intracellular roles, including regulated cell death and life-cycle progression in multicellular bacteria.
Characterization of a contractile injection system (CIS) in the Gram-positive multicellular model organism
Streptomyces coelicolor
finds that CIS mediate cell death in response to stress that impacts cellular development. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2058-5276 2058-5276 |
DOI: | 10.1038/s41564-023-01341-x |