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A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
Reciprocal regulation between SigK and differentiation programs in Streptomyces coelicolor
Xu-Ming Mao1, Zhan Zhou, Xiao-Ping Hou
1Zhejiang University, College of Life Sciences, Hangzhou 310058, China. lyq@zju.edu.cn.
Journal of Bacteriology
|September 8, 2009
Summary
Deletion of SigK, a Streptomyces coelicolor sigma factor, accelerates antibiotic production and morphological changes. SigK negatively regulates development, with its degradation releasing this inhibition.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Streptomyces coelicolor undergoes complex morphological and metabolic differentiation.
- Sigma factors regulate gene expression during bacterial development.
Purpose of the Study:
- To investigate the role of SigK (SCO6520) sigma factor in Streptomyces coelicolor development.
- To elucidate the regulatory mechanisms of SigK during morphological transition and secondary metabolism.
Main Methods:
- Gene deletion of SigK.
- Analysis of gene expression using quantitative methods.
- Protein stability assays using fusion proteins and different promoters (ermEp*, sigKp).
Main Results:
- SigK deletion led to earlier aerial mycelia formation and increased expression of developmental genes (chpE, chpH) and antibiotic biosynthesis genes (actII-orf4, redD).
- Loss of SigK enhanced production of antibiotics actinorhodin and undecylprodigiosin.
- SigK expression showed autoregulation and developmental stage-dependent stability, with decreased stability during aerial mycelia emergence.
Conclusions:
- SigK acts as a negative regulator of morphological transition and secondary metabolism in Streptomyces coelicolor.
- SigK degradation is crucial for the timely emergence of aerial mycelia, suggesting a mechanism for releasing developmental inhibition.
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