Expression profile and regulation of spore and parasporal crystal formation-associated genes in Bacillus thuringiensis.
Bacillus thuringiensis, a Gram-positive endospore-forming bacterium, is characterized by the formation of parasporal crystals consisting of insecticidal crystal proteins (ICPs) during sporulation. We reveal gene expression profiles and regulatory mechanisms associated with spore and parasporal crystal formation based on transcriptomics and proteomics data of B. thuringiensis strain CT-43. During sporulation, five ICP genes encoded by CT-43 were specifically transcribed; moreover, most of the spore structure-, assembly-, and maturation-associated genes were specifically expressed or significantly up-regulated, with significant characteristics of temporal regulation. These findings suggest that it is essential for the cell to maintain efficient operation of transcriptional and translational machinery during sporulation. Our results indicate that the RNA polymerase complex δ and ω subunits, cold shock proteins, sigma factors, and transcriptional factors as well as the E2 subunit of the pyruvate dehydrogenase complex could cooperatively participate in transcriptional regulation via different mechanisms. In particular, differences in processing and modification of ribosomal proteins, rRNA, and tRNA combined with derepression of translational inhibition could boost the rate of ribosome recycling and assembly as well as translation initiation, elongation, and termination efficiency, thereby compensating for the reduction in ribosomal levels. The efficient operation of translational machineries and powerful protein-quality controlling systems would thus ensure biosyntheses of a large quantity of proteins with normal biological functions during sporulation.
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University , No. 1 Shizishan Street, Wuhan, Hubei 430070, China.
Jieping
J
Wang
Han
H
Mei
Hongliang
H
Qian
Qing
Q
Tang
Xiaocui
X
Liu
Ziniu
Z
Yu
Jin
J
He
D001413:Bacillus thuringiensis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D057773:Cold Shock Proteins and Peptides / Q000235:genetics / Q000378:metabolism; D003460:Crystallization; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D058977:Molecular Sequence Annotation; D014176:Protein Biosynthesis; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011768:Pyruvate Dehydrogenase Complex / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D013171:Spores, Bacterial / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D057773:Cold Shock Proteins and Peptides; D021122:Protein Subunits; D011768:Pyruvate Dehydrogenase Complex; D012269:Ribosomal Proteins; D012808:Sigma Factor; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases