A Conserved Regulatory Circuit Controls Large Adhesins in Vibrio cholerae

Kitts, Giordan; Giglio, Krista M.; Zamorano‐Sánchez, David; Park, Jin Hwan; Townsley, Loni; Cooley, Richard B.; Wucher, Benjamin R.; Klose, Karl E.; Nadell, Carey D.; Yildiz, Fitnat H.; Sondermann, Holger

doi:10.1128/mbio.02822-19

“…(25) When c-di-GMP levels fall, LapD releases LapG, and LapG cleaves FrhA and CraA facilitating cell detachment from biofilms. (25) Our results are consistent with this mechanism; in the absence of LapG, FrhA and CraA remain intact, and V. cholerae cells cannot properly exit the biofilm state. To verify that the established c-di-GMP-dependent regulatory mechanism controls LapG activity in our assay, we deleted lapD ( Figure 3C).…”

Section: Matrix Disassembly Mediates V Cholerae Exit From Biofilmssupporting

confidence: 88%

“…The LapG mechanism is known: When c-di-GMP concentrations are high, the FrhA and CraA adhesins are localized to the outer membrane where they facilitate attachments that are important for biofilm formation ( Figure 3C). (25,26) Under this condition, LapG is sequestered and inactivated by the inner membrane c-di-GMP sensing protein LapD. (25) When c-di-GMP levels fall, LapD releases LapG, and LapG cleaves FrhA and CraA facilitating cell detachment from biofilms.…”

Section: Matrix Disassembly Mediates V Cholerae Exit From Biofilmsmentioning

confidence: 99%

Identification of signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

Bridges

¹

,

Fei

²

,

Bassler

³

2020

Preprint

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Bacteria alternate between being free-swimming and existing as members of sessile multicellular communities called biofilms. The biofilm lifecycle occurs in three stages: cell attachment, biofilm maturation, and biofilm dispersal. Vibrio cholerae biofilms are hyper-infectious and biofilm formation and dispersal are considered central to disease transmission. While biofilm formation is well-studied, almost nothing is known about biofilm dispersal. Here, we conduct an imaging screen for V. cholerae mutants that fail to disperse, revealing three classes of dispersal components: signal transduction proteins, matrix-degradation enzymes, and motility factors. Signaling proteins dominated the screen and among them, we focused on an uncharacterized two-component sensory system that we name DbfS/DbfR for Dispersal of Biofilm Sensor/Regulator. Phospho-DbfR represses biofilm dispersal. DbfS dephosphorylates and thereby inactivates DbfR, which permits dispersal. Matrix degradation requires two enzymes: LapG, which cleaves adhesins, and RbmB, which digests matrix polysaccharide. Reorientations in swimming direction, mediated by CheY3, are necessary for cells to escape from the porous biofilm matrix. We suggest that these components act sequentially: signaling launches dispersal by terminating matrix production and triggering matrix digestion and, subsequently, cell motility permits escape from biofilms. This study lays the groundwork for interventions that modulate V. cholerae biofilm dispersal to ameliorate disease.Significance statementThe pathogen Vibrio cholerae alternates between the free-swimming state and existing in sessile multicellular communities known as biofilms. Transitioning between these lifestyles is key for disease transmission. V. cholerae biofilm formation is well studied, however, almost nothing is known about how V. cholerae cells disperse from biofilms, precluding understanding of a central pathogenicity step. Here, we conducted a high-content imaging screen for V. cholerae mutants that failed to disperse. Our screen revealed three classes of components required for dispersal: signal transduction, matrix degradation, and motility factors. We characterized these components to reveal the sequence of molecular events that choreograph V. cholerae biofilm dispersal. Our report provides a framework for developing strategies to modulate biofilm dispersal to prevent or treat disease.

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“…3C). 25,26 Under this condition, LapG is sequestered and inactivated by the inner membrane c-di-GMP sensing protein LapD. 25 When c-di-GMP levels fall, LapD releases LapG, and LapG cleaves FrhA and CraA facilitating cell detachment from biofilms.…”

Section: Matrix Disassembly Mediates V Cholerae Exit From Biofilmsmentioning

confidence: 99%

“…25,26 Under this condition, LapG is sequestered and inactivated by the inner membrane c-di-GMP sensing protein LapD. 25 When c-di-GMP levels fall, LapD releases LapG, and LapG cleaves FrhA and CraA facilitating cell detachment from biofilms. 25 Our results are consistent with this mechanism; in the absence of LapG, FrhA and CraA remain intact, and V. cholerae cells cannot properly exit the biofilm state.…”

Section: Matrix Disassembly Mediates V Cholerae Exit From Biofilmsmentioning

confidence: 99%

“…25 When c-di-GMP levels fall, LapD releases LapG, and LapG cleaves FrhA and CraA facilitating cell detachment from biofilms. 25 Our results are consistent with this mechanism; in the absence of LapG, FrhA and CraA remain intact, and V. cholerae cells cannot properly exit the biofilm state. To verify that the established c-di-GMP-dependent regulatory mechanism controls LapG activity in our assay, we deleted lapD (Fig.…”

Section: Matrix Disassembly Mediates V Cholerae Exit From Biofilmsmentioning

confidence: 99%

See 1 more Smart Citation

Identification and analysis of the signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

Bridges¹,

Fei²,

Bassler³

2020

Preprint

0

View full text Add to dashboard Cite

Bacteria alternate between being free-swimming and existing as members of sessile multicellular communities called biofilms. The biofilm lifecycle occurs in three stages: cell attachment, biofilm maturation, and biofilm dispersal. Vibrio cholerae biofilms are hyper-infectious and biofilm formation and dispersal are considered central to disease transmission. While biofilm formation is well-studied, almost nothing is known about biofilm dispersal. Here, we conduct an imaging screen for V. cholerae mutants that fail to disperse, revealing three classes of dispersal components: signal transduction proteins, matrix-degradation enzymes, and motility factors. Signaling proteins dominated the screen and among them, we focused on an uncharacterized two-component sensory system that we name DbfS/DbfR for Dispersal of Biofilm Sensor/Regulator. Phospho-DbfR represses biofilm dispersal. DbfS dephosphorylates and thereby inactivates DbfR, which permits dispersal. Matrix degradation requires two enzymes: LapG, which cleaves adhesins, and RbmB, which digests matrix polysaccharide. Reorientations in swimming direction, mediated by CheY3, are necessary for cells to escape from the porous biofilm matrix. We suggest that these components act sequentially: signaling launches dispersal by terminating matrix production and triggering matrix digestion and, subsequently, cell motility permits escape from biofilms. This study lays the groundwork for interventions that modulate V. cholerae biofilm dispersal to ameliorate disease.

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The global regulation of c‐di‐GMP and cAMP in bacteria

Liu,

Shi,

Jensen

et al. 2024

mLife

0

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Nucleotide second messengers are highly versatile signaling molecules that regulate a variety of key biological processes in bacteria. The best‐studied examples are cyclic AMP (cAMP) and bis‐(3′–5′)‐cyclic dimeric guanosine monophosphate (c‐di‐GMP), which both act as global regulators. Global regulatory frameworks of c‐di‐GMP and cAMP in bacteria show several parallels but also significant variances. In this review, we illustrate the global regulatory models of the two nucleotide second messengers, compare the different regulatory frameworks between c‐di‐GMP and cAMP, and discuss the mechanisms and physiological significance of cross‐regulation between c‐di‐GMP and cAMP. c‐di‐GMP responds to numerous signals dependent on a great number of metabolic enzymes, and it regulates various signal transduction pathways through its huge number of effectors with varying activities. In contrast, due to the limited quantity, the cAMP metabolic enzymes and its major effector are regulated at different levels by diverse signals. cAMP performs its global regulatory function primarily by controlling the transcription of a large number of genes via cAMP receptor protein (CRP) in most bacteria. This review can help us understand how bacteria use the two typical nucleotide second messengers to effectively coordinate and integrate various physiological processes, providing theoretical guidelines for future research.

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A Conserved Regulatory Circuit Controls Large Adhesins in Vibrio cholerae

Cited by 33 publications

References 87 publications

Identification of signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

Identification of signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

Identification and analysis of the signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

The global regulation of c‐di‐GMP and cAMP in bacteria

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