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Ali MRK, Wu Y, Chapman S, Ding Y. Synthesis, structure evolution, and optical properties of gold nanobones. RESEARCH ON CHEMICAL INTERMEDIATES 2019. [DOI: 10.1007/s11164-019-03884-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lin P, Pu Q, Shen G, Li R, Guo K, Zhou C, Liang H, Jiang J, Wu M. CdpR Inhibits CRISPR-Cas Adaptive Immunity to Lower Anti-viral Defense while Avoiding Self-Reactivity. iScience 2019; 13:55-68. [PMID: 30822746 PMCID: PMC6393702 DOI: 10.1016/j.isci.2019.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 09/26/2018] [Accepted: 02/06/2019] [Indexed: 12/25/2022] Open
Abstract
CRISPR-Cas systems as adaptive immunity in bacteria and archaea battle against bacteriophages. However, little is known how CRISPR-Cas systems are precisely regulated to effectively eliminate intruders while not inducing self-reactivity. Here, we identify intrinsic negative modulator of CRISPR-Cas that influences interference and adaptation functions. LasI/RhlI-derived autoinducers activate cas operon by enhancing the binding of virulence factor regulator (Vfr) cis-response elements to cas1 promoter, whereas CdpR represses this intracellular signaling and blocks transcription of cas operon. Importantly, inhibition of Vfr reduces cas1 expression and impairs immunization and immune memory mediated by CRISPR-Cas, leading to more severe phage infection but lower self-targeting activities. In addition, CdpR-mediated LasI/RhlI/Vfr intracellular signaling represses cleavage of bacterial endogenous sequences by impeding Cas3 RNA cleavage activity. Thus, CdpR renders important inhibitory effects on CRISPR-Cas systems to avoid possible self-reactivity but potentially heightening infection risk. Our study provides insight into fine regulation of CRISPR-Cas systems for maintaining homeostasis. Both CRISPR-Cas immunization and immunity are suppressed by CdpR CdpR prevents bacterial defense to phage infection via CRISPR-Cas systems CdpR represses QS to modify CRISPR-Cas functionality in a Vfr-dependent manner CdpR blocks Vfr binding to cis-response elements in the promoter of cas operon
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Affiliation(s)
- Ping Lin
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing 400042, P. R. China; Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203-9037, USA
| | - Qinqin Pu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203-9037, USA
| | - Guanwang Shen
- Biological Science Research Center, Southwest University, Chongqing 400715, P. R. China
| | - Rongpeng Li
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203-9037, USA; Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China
| | - Kai Guo
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203-9037, USA
| | - Chuanmin Zhou
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203-9037, USA
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShaanXi 710069, P. R. China.
| | - Jianxin Jiang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing 400042, P. R. China.
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203-9037, USA.
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Abstract
Quorum sensing is a vital property of bacteria that enables community-wide coordination of collective behaviors. A key example of such a behavior is biofilm formation, in which groups of bacteria invest in synthesizing a protective, joint extracellular matrix. Quorum sensing involves the production, release, and subsequent detection of extracellular signaling molecules called autoinducers. The architecture of quorum-sensing signal transduction pathways is highly variable among different species of bacteria, but frequently involves posttranscriptional regulation carried out by small regulatory RNA molecules. This review illustrates the diverse roles small trans-acting regulatory RNAs can play, from constituting a network's core to auxiliary roles in adjusting the rate of autoinducer synthesis, mediating cross talk among different parts of a network, or integrating different regulatory inputs to trigger appropriate changes in gene expression. The emphasis is on describing how the study of small RNA-based regulation in quorum sensing and biofilm formation has uncovered new general properties or expanded our understanding of bacterial riboregulation.
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