Proteasome involvement in a complex cascade mediating SigT degradation during differentiation of Streptomyces coelicolor.
In Streptomyces coelicolor, the ECF sigma factor SigT negatively regulates cell differentiation, and is degraded by ClpP protease in a dual positive feedback manner. Here we further report that the proteasome is required for degradation of SigT, but not for degradation of its anti-sigma factor RstA, and RstA can protect SigT from degradation independent of the proteasome. Meanwhile, deletion of the proteasome showed reduced production of secondary metabolites, and the fermentation medium from wild type could promote SigT degradation. Furthermore, overexpression of redD or actII-orf4 in the proteasome-deficiency mutant resulted in SigT degradation and over-production of both undecylprodigiosin and actinorhodin. Therefore the proteasome is required for SigT degradation by affecting the production of secondary metabolites during cell differentiation.
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China; Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Xu-Ming
XM
Mao
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China.
Ni-Ni
NN
Ren
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China.
Ning
N
Sun
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China.
Feng
F
Wang
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China.
Ri-Cheng
RC
Zhou
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Yi
Y
Tang
Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China. Electronic address: lyq@zju.edu.cn.
Yong-Quan
YQ
Li
D000880:Anthraquinones / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002454:Cell Differentiation; D011353:Prodigiosin / Q000031:analogs & derivatives / Q000096:biosynthesis; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D059748:Proteolysis; D012808:Sigma Factor / Q000378:metabolism*; D048372:Streptomyces coelicolor / Q000166:cytology* / Q000378:metabolism*; D000095622:Benzoisochromanequinones
D000880:Anthraquinones; D001426:Bacterial Proteins; D011353:Prodigiosin; D046988:Proteasome Endopeptidase Complex; D012808:Sigma Factor; C047347:undecylprodigiosin; C013390:actinorhodin; D000095622:Benzoisochromanequinones
Cell differentiation; ClpP protease; Proteasome; Protein degradation; Sigma factor; Streptomyces