The function and regulation of genes required for extracellular polysaccharide synthesis and virulence in Pseudomonas solanacearum

Kao, C. Cheng

doi:10.1007/978-94-011-0746-4_7

Developments in Plant Pathology

1994

DOI: 10.1007/978-94-011-0746-4_7

|View full text |Cite

The function and regulation of genes required for extracellular polysaccharide synthesis and virulence in Pseudomonas solanacearum

C. Cheng Kao¹

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1995

Publication Types

Select...

Article2

Relationship

Self Cite0

Independent2

Authors

Journals

Cited by 2 publications

(1 citation statement)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Production of EPS I requires the 18-kb eps gene cluster, which encodes several membrane-associated and soluble polypeptides involved in its biosynthesis and export (11,22,46). Synthesis of EPS I and O antigen of P. solanacearum also involves portions of the ops gene cluster, which may encode synthesis of a common sugar precursor (10,29,30).…”

mentioning

confidence: 99%

A complex network regulates expression of eps and other virulence genes of Pseudomonas solanacearum

et al. 1995

View full text Add to dashboard Cite

We have discovered an unusual and complex regulatory network used by the phytopathogen Pseudomonas solanacearum to control transcription of eps, which encodes for production of its primary virulence factor, the exopolysaccharide EPS I. The major modules of this network were shown to be three separate signal transduction systems: PhcA, a LysR-type transcriptional regulator, and dual two-component regulatory systems, VsrA/VsrD and VsrB/VsrC. Using lacZ fusions and RNA analysis, we found that both PhcA and VsrA/VsrD control transcription of another network component, xpsR, which in turn acts in conjunction with vsrB/vsrC to increase transcription of the eps promoter by >25-fold. Moreover, gel shift DNA binding assays showed that PhcA specifically binds to the xpsR promoter region. Thus, the unique XpsR protein interconnects the three signal transduction systems, forming a network for convergent control of EPS I in simultaneous response to multiple environmental inputs. In addition, we demonstrate that each individual signaling system of the network also acts independently to divergently regulate other unique sets of virulence factors. The purpose of this complex network may be to allow this phytopathogen to both coordinately or independently regulate diverse virulence factors in order to cope with the dynamic situations and conditions encountered during interactions with plants.

show abstract

mentioning

confidence: 99%

A complex network regulates expression of eps and other virulence genes of Pseudomonas solanacearum

et al. 1995

View full text Add to dashboard Cite

show abstract

Molecular characterization of the eps gene cluster of Pseudomonas solanacearum and its transcriptional regulation at a single promoter

Huang

Schell

1995

Molecular Microbiology

View full text Add to dashboard Cite

Production of EPS I, an unusual exopolysaccharide virulence factor of the phytopathogen Pseudomonas solanacearum, requires the 18 kb eps gene cluster. DNA sequence analysis of the first seven genes of eps (epsAPBCDEF), subcellular localization of their products in maxicells, and phoA fusion analysis showed that: (i) epsA, epsB, epsE, and epsF encode exported or membrane-associated proteins probably involved in polymerization and/or export of EPS I; (ii) epsC and epsD encode soluble enzymes probably involved in synthesis of sugar components of EPS I (N-acetylgalactosaminuronic acid and possibly N-acetyltrideoxygalactose, respectively); and (iii) epsP probably encodes a phosphatase involved in EPS I production in an unknown way. Non-polar insertional mutagenesis showed that most, if not all, of these eps genes are absolutely required for production of EPS I. Using random eps::lacZ fusions and primer extension we located a transcription start site and promoter upstream of epsA. Analysis of a plasmid with this promoter fused to lacZ showed that a 140 bp regulatory region upstream of the eps transcription start site was sufficient for normal regulation of eps transcription by the multicomponent virulence gene regulatory network of P. solanacearum. Deletion of this eps promoter from a plasmid-borne epsAPBCDE::lacZ fusion reduced its expression 10-fold, indicating that this promoter alone is responsible for regulated transcription of an eps operon composed of at least epsAPBCDE. Analysis of genomic and plasmid-borne eps::lacZ fusions suggested that most remaining eps genes are part of this same operon or, and this is less likely, comprise a second co-ordinately regulated eps operon.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

The function and regulation of genes required for extracellular polysaccharide synthesis and virulence in Pseudomonas solanacearum

Cited by 2 publications

References 65 publications

A complex network regulates expression of eps and other virulence genes of Pseudomonas solanacearum

A complex network regulates expression of eps and other virulence genes of Pseudomonas solanacearum

Molecular characterization of the eps gene cluster of Pseudomonas solanacearum and its transcriptional regulation at a single promoter

Contact Info

Product

Resources

About