Negative feedback loops involving small regulatory RNAs precisely control the Vibrio harveyi qourum-sensing response

TY - JOUR

T1 - Negative feedback loops involving small regulatory RNAs precisely control the Vibrio harveyi qourum-sensing response

AU - Tu, Kimberly C.

AU - Long, Tao

AU - Svenningsen, Sine Lo

AU - Wingreen, Ned S.

AU - Bassler, Bonnie L.

PY - 2010/2/26

Y1 - 2010/2/26

N2 - Quorum sensing (QS) bacteria assess population density through secretion and detection of molecules called autoinducers (AIs). We identify and characterize two Vibrio harveyi negative feedback loops that facilitate precise transitions between low-cell-density (LCD) and high-cell-density (HCD) states. The QS central regulator LuxO autorepresses its own transcription and the Qrr small regulatory RNAs (sRNAs) posttranscriptionally repress luxO. Disrupting feedback increases the concentration of AIs required for cells to transit from LCD to HCD QS modes. Thus, the two cooperative negative feedback loops determine the point at which V. harveyi has reached a quorum and control the range of AIs over which the transition occurs. Negative feedback regulation also constrains the range of QS output – by preventing sRNA levels from becoming too high and preventing luxO mRNA levels from reaching zero. We suggest that sRNA-mediated feedback regulation is a network design feature that permits fine-tuning of gene regulation and maintenance of homeostasis.

AB - Quorum sensing (QS) bacteria assess population density through secretion and detection of molecules called autoinducers (AIs). We identify and characterize two Vibrio harveyi negative feedback loops that facilitate precise transitions between low-cell-density (LCD) and high-cell-density (HCD) states. The QS central regulator LuxO autorepresses its own transcription and the Qrr small regulatory RNAs (sRNAs) posttranscriptionally repress luxO. Disrupting feedback increases the concentration of AIs required for cells to transit from LCD to HCD QS modes. Thus, the two cooperative negative feedback loops determine the point at which V. harveyi has reached a quorum and control the range of AIs over which the transition occurs. Negative feedback regulation also constrains the range of QS output – by preventing sRNA levels from becoming too high and preventing luxO mRNA levels from reaching zero. We suggest that sRNA-mediated feedback regulation is a network design feature that permits fine-tuning of gene regulation and maintenance of homeostasis.

U2 - 10.1016/j.molcel.2010.01.022

DO - 10.1016/j.molcel.2010.01.022

M3 - Journal article

C2 - 20188674

SN - 1097-2765

VL - 37

SP - 567

EP - 579

JO - Molecular Cell

JF - Molecular Cell

IS - 4

ER -