HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (Papers in Press[PDF]) All Versions of this Article: mic.0.027862-0v1 155/7/2197    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Hara, H. Articles by Horinouchi, S. Search for Related Content PubMed PubMed Citation Articles by Hara, H. Articles by Horinouchi, S. Agricola Articles by Hara, H. Articles by Horinouchi, S.

DNA microarray analysis of global gene regulation by A-factor in Streptomyces griseus

University of Tokyo

ABSTRACT

A-factor (2-isocapryloyl-3R-hydroxymethyl--butyrolactone) is a microbial hormone that triggers morphological differentiation and secondary metabolism in Streptomyces griseus. The effects of A-factor on global gene expression were determined by DNA microarray analysis of transcriptomes obtained with the A-factor-deficient mutant afsA. A-factor was added at a concentration of 25 ng?ml^-1 to mutant afsA at the middle of the exponential growth phase, and RNA samples were prepared from the cells grown further for 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, and 12 h after A-factor addition. The effects of A-factor on transcription of all genes of S. griseus were evaluated by comparison of the transcriptomes to those obtained from the cells grown in the absence of A-factor. Analysis of variance among the transcriptomes revealed that 477 genes, which were dispersed throughout the chromosome, were differentially expressed during the 12 h after addition of A-factor, when evaluated with specific criteria. Quality threshold-clustering analysis with regard to putative polycistronic transcriptional units and levels of upregulation predicted that 152 genes belonging to 74 transcriptional units were probable A-factor-inducible genes. Competitive electrophoretic mobility shift assays using DNA fragments including putative promoter regions of these 74 transcriptional units suggested that AdpA bound 36 regions to activate 72 genes in total. Many of these A-factor-inducible genes encoded proteins of unknown function, suggesting that the A-factor regulatory cascade of S. griseus affects gene expression at a specific time point more profoundly than expected.

¹ E-mail: asuhori{at}mail.ecc.u-tokyo.ac.jp