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Updated: Aug 22, 2026

Fluorescence Live-cell Imaging of the Complete Vegetative Cell Cycle of the Slow-growing Social Bacterium Myxococcus xanthus
11:45

Fluorescence Live-cell Imaging of the Complete Vegetative Cell Cycle of the Slow-growing Social Bacterium Myxococcus xanthus

Published on: June 20, 2018

The high-mobility group A-type protein CarD of the bacterium Myxococcus xanthus as a transcription factor for several

Marisa Galbis-Martínez1, Marta Fontes, Francisco J Murillo

  • 1Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain.

Genetics
|September 3, 2004
PubMed

Insights

CarD protein regulates gene expression in bacteria, impacting processes like carotenoid synthesis and development. A mutation in CarD affects multiple genes, suggesting a central role in bacterial regulatory networks.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • CarD is a unique prokaryotic protein resembling eukaryotic high-mobility group A transcription factors.
  • CarD is primarily found in myxobacteria and regulates light-induced carotenoid synthesis and starvation-induced development in *Myxococcus xanthus*.

Purpose of the Study:

  • To investigate the role of CarD in regulating gene expression during vegetative growth in *Myxococcus xanthus*.
  • To identify genes and regulatory mechanisms influenced by CarD function.

Main Methods:

  • A loss-of-function mutation in the *carD* gene (*carD1*) was created.
  • The effect of the *carD1* mutation on the expression of random *lacZ*-tagged genes was analyzed.
  • Suppressor mutations affecting *carD1* phenotypes were isolated and characterized.

Main Results:

  • The *carD1* mutation significantly altered the expression of numerous vegetative genes, downregulating some and upregulating others.
  • Several suppressor mutations were identified, with one (*sud-2*) affecting multiple *carD1*-sensitive genes and developmental processes.
  • The *sud-2* mutation suggests CarD and the Sud-2 protein function within a shared regulatory mechanism.

Conclusions:

  • CarD plays a substantial role in the transcriptional regulation of diverse genes during vegetative growth.
  • CarD is involved in a common regulatory pathway that influences various cellular processes, including gene expression and development.
  • The identification of suppressor mutations provides insights into the molecular mechanism underlying CarD's regulatory functions.

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