A contractile injection system is required for developmentally regulated cell death in Streptomyces coelicolor

• Published in: Nature communications 2023-03, Vol.14 (1), p.1469-1469, Article 1469
• Main Authors: Vladimirov, Maria, Zhang, Ruo Xi, Mak, Stefanie, Nodwell, Justin R., Davidson, Alan R.
• Format: Article
• Language: English
• Subjects: 14/28; 14/34; 14/63; 631/326/1321; 631/326/41/2528; 631/326/88; 82/16; 82/58; 82/80; 82/83; Apoptosis; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cell death; Contractility; Cytology; Cytotoxicity; Deficient mutant; Gene Expression Regulation, Bacterial; Humanities and Social Sciences; Hyphae; Injection; Injection systems; multidisciplinary; Phages; Proteins; Regulated Cell Death; Science; Science (multidisciplinary); Spores, Bacterial - metabolism; Sporulation; Streptomyces; Streptomyces coelicolor; Streptomyces coelicolor - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-37087-7

Diverse bacterial species produce extracellular contractile injection systems (eCISs). Although closely related to contractile phage tails, eCISs can inject toxic proteins into eukaryotic cells. Thus, these systems are commonly viewed as cytotoxic defense mechanisms that are not central to other aspects of bacterial biology. Here, we provide evidence that eCISs appear to participate in the complex developmental process of the bacterium Streptomyces coelicolor . In particular, we show that S. coelicolor produces eCIS particles during its normal growth cycle, and that strains lacking functional eCIS particles exhibit pronounced alterations in their developmental program. Furthermore, eCIS-deficient mutants display reduced levels of cell death and altered morphology during growth in liquid media. Our results suggest that the main role of eCISs in S. coelicolor is to modulate the developmental switch that leads to aerial hyphae formation and sporulation, rather than to attack other species. Bacteria can use extracellular contractile injection systems (eCISs) to inject toxic proteins into eukaryotic cells. Here, Vladimirov et al. provide evidence that the main role of eCISs in Streptomyces is not to attack other species, but to modulate the complex Streptomyces developmental process.