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Lrp acts as both a positive and negative regulator for type 1 fimbriae production in Salmonella enterica serovar Typhimurium.
PLoS One. 2011; 6(10):e26896.Plos

Abstract

Leucine-responsive regulatory protein (Lrp) is known to be an indirect activator of type 1 fimbriae synthesis in Salmonella enterica serovar Typhimurium via direct regulation of FimZ, a direct positive regulator for type 1 fimbriae production. Using RT-PCR, we have shown previously that fimA transcription is dramatically impaired in both lrp-deletion (Δlrp) and constitutive-lrp expression (lrp(C)) mutant strains. In this work, we used chromosomal P(fimA)-lacZ fusions and yeast agglutination assays to confirm and extend our previous results. Direct binding of Lrp to P(fimA) was shown by an electrophoretic mobility shift assay (EMSA) and DNA footprinting assay. Site-directed mutagenesis revealed that the Lrp-binding motifs in P(fimA) play a role in both activation and repression of type 1 fimbriae production. Overproduction of Lrp also abrogates fimZ expression. EMSA data showed that Lrp and FimZ proteins independently bind to P(fimA) without competitive exclusion. In addition, both Lrp and FimZ binding to P(fimA) caused a hyper retardation (supershift) of the DNA-protein complex compared to the shift when each protein was present alone. Nutrition-dependent cellular Lrp levels closely correlated with the amount of type 1 fimbriae production. These observations suggest that Lrp plays important roles in type 1 fimbriation by acting as both a positive and negative regulator and its effect depends, at least in part, on the cellular concentration of Lrp in response to the nutritional environment.

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Authors+Show Affiliations

Baek CH
The Biodesign Institute at Arizona State University, Tempe, Arizona, United States of America.
Kang HY
No affiliation info available
Roland KL
No affiliation info available
Curtiss R
No affiliation info available

MeSH

Antigens, BacterialFimbriae ProteinsFimbriae, BacterialGene Expression Regulation, BacterialLeucine-Responsive Regulatory ProteinProtein BindingSalmonella typhimurium

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

22046399

Citation

Baek, Chang-Ho, et al. "Lrp Acts as Both a Positive and Negative Regulator for Type 1 Fimbriae Production in Salmonella Enterica Serovar Typhimurium." PloS One, vol. 6, no. 10, 2011, pp. e26896.
Baek CH, Kang HY, Roland KL, et al. Lrp acts as both a positive and negative regulator for type 1 fimbriae production in Salmonella enterica serovar Typhimurium. PLoS One. 2011;6(10):e26896.
Baek, C. H., Kang, H. Y., Roland, K. L., & Curtiss, R. (2011). Lrp acts as both a positive and negative regulator for type 1 fimbriae production in Salmonella enterica serovar Typhimurium. PloS One, 6(10), e26896. https://doi.org/10.1371/journal.pone.0026896
Baek CH, et al. Lrp Acts as Both a Positive and Negative Regulator for Type 1 Fimbriae Production in Salmonella Enterica Serovar Typhimurium. PLoS One. 2011;6(10):e26896. PubMed PMID: 22046399.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Lrp acts as both a positive and negative regulator for type 1 fimbriae production in Salmonella enterica serovar Typhimurium. AU - Baek,Chang-Ho, AU - Kang,Ho-Young, AU - Roland,Kenneth L, AU - Curtiss,Roy,3rd Y1 - 2011/10/28/ PY - 2011/08/23/received PY - 2011/10/05/accepted PY - 2011/11/3/entrez PY - 2011/11/3/pubmed PY - 2012/3/27/medline SP - e26896 EP - e26896 JF - PloS one JO - PLoS One VL - 6 IS - 10 N2 - Leucine-responsive regulatory protein (Lrp) is known to be an indirect activator of type 1 fimbriae synthesis in Salmonella enterica serovar Typhimurium via direct regulation of FimZ, a direct positive regulator for type 1 fimbriae production. Using RT-PCR, we have shown previously that fimA transcription is dramatically impaired in both lrp-deletion (Δlrp) and constitutive-lrp expression (lrp(C)) mutant strains. In this work, we used chromosomal P(fimA)-lacZ fusions and yeast agglutination assays to confirm and extend our previous results. Direct binding of Lrp to P(fimA) was shown by an electrophoretic mobility shift assay (EMSA) and DNA footprinting assay. Site-directed mutagenesis revealed that the Lrp-binding motifs in P(fimA) play a role in both activation and repression of type 1 fimbriae production. Overproduction of Lrp also abrogates fimZ expression. EMSA data showed that Lrp and FimZ proteins independently bind to P(fimA) without competitive exclusion. In addition, both Lrp and FimZ binding to P(fimA) caused a hyper retardation (supershift) of the DNA-protein complex compared to the shift when each protein was present alone. Nutrition-dependent cellular Lrp levels closely correlated with the amount of type 1 fimbriae production. These observations suggest that Lrp plays important roles in type 1 fimbriation by acting as both a positive and negative regulator and its effect depends, at least in part, on the cellular concentration of Lrp in response to the nutritional environment. SN - 1932-6203 UR - https://www.unboundmedicine.com/medline/citation/22046399/Lrp_acts_as_both_a_positive_and_negative_regulator_for_type_1_fimbriae_production_in_Salmonella_enterica_serovar_Typhimurium_ L2 - https://dx.plos.org/10.1371/journal.pone.0026896 DB - PRIME DP - Unbound Medicine ER -