51
|
Jubelin G, Chavez CV, Taieb F, Banfield MJ, Samba-Louaka A, Nobe R, Nougayrède JP, Zumbihl R, Givaudan A, Escoubas JM, Oswald E. Cycle inhibiting factors (CIFs) are a growing family of functional cyclomodulins present in invertebrate and mammal bacterial pathogens. PLoS One 2009; 4:e4855. [PMID: 19308257 PMCID: PMC2654923 DOI: 10.1371/journal.pone.0004855] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Accepted: 02/16/2009] [Indexed: 01/04/2023] Open
Abstract
The cycle inhibiting factor (Cif) produced by enteropathogenic and enterohemorrhagic Escherichia coli was the first cyclomodulin to be identified that is injected into host cells via the type III secretion machinery. Cif provokes cytopathic effects characterized by G1 and G2 cell cycle arrests, accumulation of the cyclin-dependent kinase inhibitors (CKIs) p21waf1/cip1 and p27kip1 and formation of actin stress fibres. The X-ray crystal structure of Cif revealed it to be a divergent member of a superfamily of enzymes including cysteine proteases and acetyltransferases that share a conserved catalytic triad. Here we report the discovery and characterization of four Cif homologs encoded by different pathogenic or symbiotic bacteria isolated from vertebrates or invertebrates. Cif homologs from the enterobacteria Yersinia pseudotuberculosis, Photorhabdus luminescens, Photorhabdus asymbiotica and the β-proteobacterium Burkholderia pseudomallei all induce cytopathic effects identical to those observed with Cif from pathogenic E. coli. Although these Cif homologs are remarkably divergent in primary sequence, the catalytic triad is strictly conserved and was shown to be crucial for cell cycle arrest, cytoskeleton reorganization and CKIs accumulation. These results reveal that Cif proteins form a growing family of cyclomodulins in bacteria that interact with very distinct hosts including insects, nematodes and humans.
Collapse
Affiliation(s)
- Grégory Jubelin
- INRA, UMR1225, Toulouse, France
- Université de Toulouse, ENVT, UMR 1225, Toulouse, France
| | - Carolina Varela Chavez
- INRA, UMR 1133 Laboratoire EMIP, Montpellier, France
- Université Montpellier 2, UMR 1133 Laboratoire EMIP, Montpellier, France
| | - Frédéric Taieb
- INRA, UMR1225, Toulouse, France
- Université de Toulouse, ENVT, UMR 1225, Toulouse, France
| | - Mark J. Banfield
- Department of Biological Chemistry, John Innes Centre, NR4 7UH, Norwich, United Kingdom
| | - Ascel Samba-Louaka
- INRA, UMR1225, Toulouse, France
- Université de Toulouse, ENVT, UMR 1225, Toulouse, France
| | - Rika Nobe
- INRA, UMR1225, Toulouse, France
- Université de Toulouse, ENVT, UMR 1225, Toulouse, France
| | | | - Robert Zumbihl
- INRA, UMR 1133 Laboratoire EMIP, Montpellier, France
- Université Montpellier 2, UMR 1133 Laboratoire EMIP, Montpellier, France
| | - Alain Givaudan
- INRA, UMR 1133 Laboratoire EMIP, Montpellier, France
- Université Montpellier 2, UMR 1133 Laboratoire EMIP, Montpellier, France
| | - Jean-Michel Escoubas
- INRA, UMR 1133 Laboratoire EMIP, Montpellier, France
- Université Montpellier 2, UMR 1133 Laboratoire EMIP, Montpellier, France
| | - Eric Oswald
- INRA, UMR1225, Toulouse, France
- Université de Toulouse, ENVT, UMR 1225, Toulouse, France
- * E-mail:
| |
Collapse
|
52
|
Abstract
Recent genetic and molecular analyses have revealed how several strategies enable bacteria to persist and overcome insect immune defences. Genetic and genomic tools that can be used with Drosophila melanogaster have enabled the characterization of the pathways that are used by insects to detect bacterial invaders and combat infection. Conservation of bacterial virulence factors and insect immune repertoires indicates that there are common strategies of host invasion and pathogen eradication. Long-term interactions of bacteria with insects might ensure efficient dissemination of pathogens to other hosts, including humans.
Collapse
|
53
|
Identification of a putative Mexican strain of Serratia entomophila pathogenic against root-damaging larvae of Scarabaeidae (Coleoptera). Appl Environ Microbiol 2007; 74:802-10. [PMID: 18083879 DOI: 10.1128/aem.01074-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The larvae of scarab beetles, known as "white grubs" and belonging to the genera Phyllophaga and Anomala (Coleoptera: Scarabaeidae), are regarded as soil-dwelling pests in Mexico. During a survey conducted to find pathogenic bacteria with the potential to control scarab larvae, a native Serratia sp. (strain Mor4.1) was isolated from a dead third-instar Phyllophaga blanchardi larva collected from a cornfield in Tres Marías, Morelos, Mexico. Oral bioassays using healthy P. blanchardi larvae fed with the Mor4.1 isolate showed that this strain was able to cause an antifeeding effect and a significant loss of weight. Mortality was observed for P. blanchardi, P. trichodes, and P. obsoleta in a multidose experiment. The Mor4.1 isolate also caused 100% mortality 24 h after intracoelomic inoculation of the larvae of P. blanchardi, P. ravida, Anomala donovani and the lepidopteran insect Manduca sexta. Oral and injection bioassays were performed with concentrated culture broths of the Mor4.1 isolate to search for disease symptoms and mortality caused by extracellular proteins. The results have shown that Mor4.1 broths produce significant antifeeding effects and mortality. Mor4.1 broths treated with proteinase K lost the ability to cause disease symptoms and mortality, in both the oral and the injection bioassays, suggesting the involvement of toxic proteins in the disease. The Mor4.1 isolate was identified as a putative Serratia entomophila Mor4.1 strain based on numerical taxonomy and phylogenetic analyses done with the 16S rRNA gene sequence. The potential of S. entomophila Mor4.1 and its toxins to be used in an integrated pest management program is discussed.
Collapse
|