The bacterial type III secretion system‐associated pilin HrpA has an unusually long mRNA half‐life

Hienonen, Elina; Rantakari, Anssi; Romantschuk, Martin; Taira, Suvi

doi:10.1016/j.febslet.2004.06.072

“…The half-lives of about 80% of the mRNAs of E. coli and B. subtilis are less than 8 min, as determined by global mRNA stability analyses (3a). Even for "stable" mRNAs, half-lives only in the range of 15 to 45 min have been reported (20,22,24). In contrast, in GAS, half-lives of SPTs ranged up to about 225 min in stationary phase.…”

Section: Discussionmentioning

confidence: 99%

Role of mRNA Stability in Growth Phase Regulation of Gene Expression in the Group A Streptococcus

Barnett

¹

,

Bugrysheva

²

,

Scott

³

2007

View full text Add to dashboard Cite

The impressive disease spectrum of Streptococcus pyogenes (the group A streptococcus [GAS]) is believed to be determined by its ability to modify gene expression in response to environmental stimuli. Virulence gene expression is controlled tightly by several different transcriptional regulators in this organism. In addition, expression of most, if not all, GAS genes is determined by a global mechanism dependent on growth phase. To begin an analysis of growth-phase regulation, we compared the transcriptome 2 h into stationary phase to that in late exponential phase of a serotype M3 GAS strain. We identified the arc transcript as more abundant in stationary phase in addition to the sag and sda transcripts that had been previously identified. We found that in stationary phase, the stability of sagA, sda, and arcT transcripts increased dramatically. We found that polynucleotide phosphorylase (PNPase [encoded by pnpA]) is rate limiting for decay of sagA and sda transcripts in late exponential phase, since the stability of these mRNAs was greater in a pnpA mutant, while stability of control mRNAs was unaffected by this mutation. Complementation restored the wild-type decay rate. Furthermore, in a pnpA mutant, the sagA mRNA appeared to be full length, as determined by Northern hybridization. It seems likely that mRNAs abundant in stationary phase are insensitive to the normal decay enzyme(s) and instead require PNPase for this process. It is possible that PNPase activity is limited in stationary phase, allowing persistence of these important virulence factor transcripts at this phase of growth.

show abstract

“…In addition to the potential role of mRNA in targeting substrates to the type III system, mRNA may have a key role in regulating the expression and stoichiometry of secreted proteins. For example, Hienonen et al [227] have reported that the mRNA of the type III pilin, HrpA has an unusually long half‐life, possibly as a result of a stable GC‐rich loop in the 3′ end of the transcript. Future sequence‐based predictions may be designed to predict both the destination and the duration of secreted proteins at both an mRNA and protein level.…”

Section: Discussionmentioning

confidence: 99%

Profiling the secretomes of plant pathogenic Proteobacteria

Preston¹,

Studholme²,

Caldelari³

2005

View full text Add to dashboard Cite

Secreted proteins are central to the success of plant pathogenic bacteria. They are used by plant pathogens to adhere to and degrade plant cell walls, to suppress plant defence responses, and to deliver bacterial DNA and proteins into the cytoplasm of plant cells. However, experimental investigations into the identity and role of secreted proteins in plant pathogenesis have been hindered by the fact that many of these proteins are only expressed or secreted in planta, that knockout mutations of individual proteins frequently have little or no obvious phenotype, and that some obligate and fastidious plant pathogens remain recalcitrant to genetic manipulation. The availability of genome sequence data for a large number of agriculturally and scientifically important plant pathogens enables us to predict and compare the complete secretomes of these bacteria. In this paper we outline strategies that are currently being used to identify secretion systems and secreted proteins in Proteobacterial plant pathogens and discuss the implications of these analyses for future investigations into the molecular mechanisms of plant pathogenesis.

show abstract

“…For example, Hienonen et al [227] have reported that the mRNA of the type III pilin, HrpA has an unusually long half-life, possibly as a result of a stable GC-rich loop in the 3 0 end of the transcript. Researchers are increasingly aware that mRNA sequence and conformation can have a significant effect on protein targeting and expression.…”

Section: Discussionmentioning

confidence: 99%

Profiling the secretomes of plant pathogenic Proteobacteria

PRESTON¹,

Studholme²,

CALDELARI³

2005

FEMS Microbiology Reviews

View full text Add to dashboard Cite

Secreted proteins are central to the success of plant pathogenic bacteria. They are used by plant pathogens to adhere to and degrade plant cell walls, to suppress plant defence responses, and to deliver bacterial DNA and proteins into the cytoplasm of plant cells. However, experimental investigations into the identity and role of secreted proteins in plant pathogenesis have been hindered by the fact that many of these proteins are only expressed or secreted in planta, that knockout mutations of individual proteins frequently have little or no obvious phenotype, and that some obligate and fastidious plant pathogens remain recalcitrant to genetic manipulation. The availability of genome sequence data for a large number of agriculturally and scientifically important plant pathogens enables us to predict and compare the complete secretomes of these bacteria. In this paper we outline strategies that are currently being used to identify secretion systems and secreted proteins in Proteobacterial plant pathogens and discuss the implications of these analyses for future investigations into the molecular mechanisms of plant pathogenesis.

show abstract

The bacterial type III secretion system‐associated pilin HrpA has an unusually long mRNA half‐life

Cited by 13 publications

References 35 publications

Role of mRNA Stability in Growth Phase Regulation of Gene Expression in the Group A Streptococcus

Role of mRNA Stability in Growth Phase Regulation of Gene Expression in the Group A Streptococcus

Profiling the secretomes of plant pathogenic Proteobacteria

Profiling the secretomes of plant pathogenic Proteobacteria

Contact Info

Product

Resources

About