Growth phase-associated changes in the transcriptome and proteome of Streptococcus pyogenes.
Streptococcus pyogenes is responsible for approximately 500,000 deaths each year worldwide. Many of the associated virulence factors are expressed in a growth phase-dependent manner. To identify growth phase-associated changes in expression on a genomescale, the exponential and stationary phase transcriptomes and proteomes of S. pyogenes strain NZ131 (serotype M49) were compared by using Affymetrix NimbleExpress gene chips and two-dimensional gel electrophoresis. At the transcript level, the expression of 689 genes, representing approximately 40% of the chromosome, differed by twofold or more between the two growth phases. The majority of transcripts that were more abundant in the early-stationary phase encoded proteins involved in energy conversion, transport, and metabolism. At the protein level, an average of 527 and 403 protein spots were detected in the exponential and stationary phases of growth, respectively. Tandem mass spectrometry was used to identify 172 protein spots, 128 of which were growth phase regulated. Enzymes involved in glycolysis and pyruvate metabolism and several stress-responsive proteins were more abundant in the stationary phase of growth. Overall, the results identified growth phase-regulated genes in strain NZ131 and revealed significant post-transcriptional complexity associated with pathogen adaptation to the stationary phase of growth.
Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Lee Medical Building, 414 East Clark Street, Vermillion, SD 57069-2390, USA.
Michelle A
MA
Chaussee
Alexander V
AV
Dmitriev
Eduardo A
EA
Callegari
Michael S
MS
Chaussee
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D013297:Streptococcus pyogenes / Q000737:chemistry / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D014158:Transcription, Genetic; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D020543:Proteome; D037521:Virulence Factors