Properties of the phage-shock-protein (Psp) regulatory complex that govern signal transduction and induction of the Psp response in Escherichia coli

The phage-shock-protein (Psp) response maintains the proton-motive force (pmf) under extracytoplasmic stress conditions that impair the inner membrane (IM) in bacterial cells. In Escherichia coli transcription of the pspABCDE and pspG genes requires activation of σ 54-RNA polymerase by the enhancer-binding protein PspF. A regulatory network comprising PspF–A–C–B–ArcB controls psp expression. One key regulatory point is the negative control of PspF imposed by its binding to PspA. It has been proposed that under stress conditions, the IM-bound sensors PspB and PspC receive and transduce the signal(s) to PspA via protein–protein interactions, resulting in the release of the PspA–PspF inhibitory complex and the consequent induction of psp. In this work we demonstrate that PspB self-associates and interacts with PspC via putative IM regions. We present evidence suggesting that PspC has two topologies and that conserved residue G48 and the putative leucine zipper motif are determinants required for PspA interaction and signal transduction upon stress. We also establish that PspC directly interacts with the effector PspG, and show that PspG self-associates. These results are discussed in the context of formation and function of the Psp regulatory complex.

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Autotransporters as Scaffolds for Novel Bacterial Adhesins: Surface Properties of Escherichia coli Cells Displaying Jun/Fos Dimerization Domains

Journal of Bacteriology ◽

10.1128/jb.185.18.5585-5590.2003 ◽

2003 ◽

Vol 185 (18) ◽

pp. 5585-5590 ◽

Cited By ~ 26

Author(s):

Esteban Veiga ◽

Víctor de Lorenzo ◽

Luis Angel Fernández

Keyword(s):

Escherichia Coli ◽

Protein Interactions ◽

Leucine Zipper ◽

Immunoglobulin A ◽

Protein Protein Interactions ◽

Leucine Zippers ◽

Bacterial Consortia ◽

Neisseria Gonorrhoea ◽

Hybrid Proteins ◽

Bacterial Adhesins

ABSTRACT Hybrid proteins containing the β-autotransporter domain of the immunoglobulin A (IgA) protease of Neisseria gonorrhoea (IgAβ) and the partner leucine zippers of the eukaryotic transcriptional factors Fos and Jun were expressed in Escherichia coli. Such fusion proteins targeted the leucine zipper modules to the cell surface. Cells displaying the Junβ sequence flocculated shortly after induction of the hybrid protein. E. coli cells expressing separately Fosβ and Junβ chimeras formed stable bacterial consortia. These associations were physically held by tight intercell ties caused by the protein-protein interactions of matching dimerization domains. The role of autotransporters in the emergence of new adhesins is discussed.

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Detecting protein–protein interactions by Xe-129 NMR

Chemical Communications ◽

10.1039/d0cc02988b ◽

2020 ◽

Vol 56 (75) ◽

pp. 11122-11125 ◽

Cited By ~ 2

Author(s):

Zhuangyu Zhao ◽

Benjamin W. Roose ◽

Serge D. Zemerov ◽

Madison A. Stringer ◽

Ivan J. Dmochowski

Keyword(s):

Protein Interactions ◽

Bioanalytical Methods ◽

Leucine Zipper ◽

Bacterial Cells ◽

Protein Protein Interactions

Detection of protein–protein interactions (PPIs) is limited by current bioanalytical methods. Reconstitution of TEM-1—promoted here by cFos/cJun leucine zipper interaction—gives rise to sensitive 129Xe NMR signal in bacterial cells.

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Roles of the 14-3-3 gene family in cotton flowering

BMC Plant Biology ◽

10.1186/s12870-021-02923-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Na Sang ◽

Hui Liu ◽

Bin Ma ◽

Xianzhong Huang ◽

Lu Zhuo ◽

...

Keyword(s):

Gene Family ◽

Protein Interactions ◽

Leucine Zipper ◽

Expression Patterns ◽

Bimolecular Fluorescence Complementation ◽

Structural Motif ◽

Virus Induced Gene Silencing ◽

Protein Protein Interactions ◽

Basic Leucine Zipper ◽

Genome Wide

Abstract Background In plants, 14-3-3 proteins, also called GENERAL REGULATORY FACTORs (GRFs), encoded by a large multigene family, are involved in protein–protein interactions and play crucial roles in various physiological processes. No genome-wide analysis of the GRF gene family has been performed in cotton, and their functions in flowering are largely unknown. Results In this study, 17, 17, 31, and 17 GRF genes were identified in Gossypium herbaceum, G. arboreum, G. hirsutum, and G. raimondii, respectively, by genome-wide analyses and were designated as GheGRFs, GaGRFs, GhGRFs, and GrGRFs, respectively. A phylogenetic analysis revealed that these proteins were divided into ε and non-ε groups. Gene structural, motif composition, synteny, and duplicated gene analyses of the identified GRF genes provided insights into the evolution of this family in cotton. GhGRF genes exhibited diverse expression patterns in different tissues. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that the GhGRFs interacted with the cotton FLOWERING LOCUS T homologue GhFT in the cytoplasm and nucleus, while they interacted with the basic leucine zipper transcription factor GhFD only in the nucleus. Virus-induced gene silencing in G. hirsutum and transgenic studies in Arabidopsis demonstrated that GhGRF3/6/9/15 repressed flowering and that GhGRF14 promoted flowering. Conclusions Here, 82 GRF genes were identified in cotton, and their gene and protein features, classification, evolution, and expression patterns were comprehensively and systematically investigated. The GhGRF3/6/9/15 interacted with GhFT and GhFD to form florigen activation complexs that inhibited flowering. However, GhGRF14 interacted with GhFT and GhFD to form florigen activation complex that promoted flowering. The results provide a foundation for further studies on the regulatory mechanisms of flowering.

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The Protein Interactome of Glycolysis in Escherichia coli

Proteomes ◽

10.3390/proteomes9020016 ◽

2021 ◽

Vol 9 (2) ◽

pp. 16

Author(s):

Shomeek Chowdhury ◽

Stephen Hepper ◽

Mudassir K. Lodi ◽

Milton H. Saier ◽

Peter Uetz

Keyword(s):

Escherichia Coli ◽

Protein Interactions ◽

Allosteric Regulation ◽

Glycolytic Enzymes ◽

Protein Protein Interactions ◽

Post Translational Modification ◽

Interacting Protein ◽

E Coli ◽

Protein Interactome ◽

The Impact

Glycolysis is regulated by numerous mechanisms including allosteric regulation, post-translational modification or protein-protein interactions (PPI). While glycolytic enzymes have been found to interact with hundreds of proteins, the impact of only some of these PPIs on glycolysis is well understood. Here we investigate which of these interactions may affect glycolysis in E. coli and possibly across numerous other bacteria, based on the stoichiometry of interacting protein pairs (from proteomic studies) and their conservation across bacteria. We present a list of 339 protein-protein interactions involving glycolytic enzymes but predict that ~70% of glycolytic interactors are not present in adequate amounts to have a significant impact on glycolysis. Finally, we identify a conserved but uncharacterized subset of interactions that are likely to affect glycolysis and deserve further study.

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Transactivation Functions of the N-Terminal Domains of Nuclear Hormone Receptors: Protein Folding and Coactivator Interactions

Molecular Endocrinology ◽

10.1210/me.2002-0258 ◽

2003 ◽

Vol 17 (1) ◽

pp. 1-10 ◽

Cited By ~ 125

Author(s):

Raj Kumar ◽

E. Brad Thompson

Keyword(s):

Dna Binding ◽

Protein Interactions ◽

Hormone Receptors ◽

Nuclear Hormone Receptor ◽

Binding Domain ◽

Dna Binding Domain ◽

Protein Protein Interactions ◽

Carboxy Terminal ◽

And Function ◽

Terminal Domains

Abstract The N-terminal domains (NTDs) of many members of the nuclear hormone receptor (NHR) family contain potent transcription-activating functions (AFs). Knowledge of the mechanisms of action of the NTD AFs has lagged, compared with that concerning other important domains of the NHRs. In part, this is because the NTD AFs appear to be unfolded when expressed as recombinant proteins. Recent studies have begun to shed light on the structure and function of the NTD AFs. Recombinant NTD AFs can be made to fold by application of certain osmolytes or when expressed in conjunction with a DNA-binding domain by binding that DNA-binding domain to a DNA response element. The sequence of the DNA binding site may affect the functional state of the AFs domain. If properly folded, NTD AFs can bind certain cofactors and primary transcription factors. Through these, and/or by direct interactions, the NTD AFs may interact with the AF2 domain in the ligand binding, carboxy-terminal portion of the NHRs. We propose models for the folding of the NTD AFs and their protein-protein interactions.

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Artificial Septal Targeting of Bacillus subtilis Cell Division Proteins in Escherichia coli: an Interspecies Approach to the Study of Protein-Protein Interactions in Multiprotein Complexes

Journal of Bacteriology ◽

10.1128/jb.00462-08 ◽

2008 ◽

Vol 190 (18) ◽

pp. 6048-6059 ◽

Cited By ~ 17

Author(s):

Carine Robichon ◽

Glenn F. King ◽

Nathan W. Goehring ◽

Jon Beckwith

Keyword(s):

Escherichia Coli ◽

Bacillus Subtilis ◽

Cell Division ◽

Protein Interactions ◽

Fluorescent Protein ◽

Bacterial Cell Division ◽

Protein Protein Interactions ◽

Positive Interaction ◽

E Coli ◽

Multiprotein Complexes

ABSTRACT Bacterial cell division is mediated by a set of proteins that assemble to form a large multiprotein complex called the divisome. Recent studies in Bacillus subtilis and Escherichia coli indicate that cell division proteins are involved in multiple cooperative binding interactions, thus presenting a technical challenge to the analysis of these interactions. We report here the use of an E. coli artificial septal targeting system for examining the interactions between the B. subtilis cell division proteins DivIB, FtsL, DivIC, and PBP 2B. This technique involves the fusion of one of the proteins (the “bait”) to ZapA, an E. coli protein targeted to mid-cell, and the fusion of a second potentially interacting partner (the “prey”) to green fluorescent protein (GFP). A positive interaction between two test proteins in E. coli leads to septal localization of the GFP fusion construct, which can be detected by fluorescence microscopy. Using this system, we present evidence for two sets of strong protein-protein interactions between B. subtilis divisomal proteins in E. coli, namely, DivIC with FtsL and DivIB with PBP 2B, that are independent of other B. subtilis cell division proteins and that do not disturb the cytokinesis process in the host cell. Our studies based on the coexpression of three or four of these B. subtilis cell division proteins suggest that interactions among these four proteins are not strong enough to allow the formation of a stable four-protein complex in E. coli in contrast to previous suggestions. Finally, our results demonstrate that E. coli artificial septal targeting is an efficient and alternative approach for detecting and characterizing stable protein-protein interactions within multiprotein complexes from other microorganisms. A salient feature of our approach is that it probably only detects the strongest interactions, thus giving an indication of whether some interactions suggested by other techniques may either be considerably weaker or due to false positives.

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Influence of High Pressure on the Dimerization of ToxR, a Protein Involved in Bacterial Signal Transduction

Applied and Environmental Microbiology ◽

10.1128/aem.02028-08 ◽

2008 ◽

Vol 74 (24) ◽

pp. 7821-7823 ◽

Cited By ~ 14

Author(s):

Kai Linke ◽

Nagarajan Periasamy ◽

Matthias Ehrmann ◽

Roland Winter ◽

Rudi F. Vogel

Keyword(s):

Escherichia Coli ◽

Signal Transduction ◽

High Pressure ◽

Structure And Function ◽

Transmembrane Segments ◽

Bacterial Signal Transduction ◽

Reporter Strains ◽

And Function ◽

First Time

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.

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Leucine periodicity of U2 small nuclear ribonucleoprotein particle (snRNP) A' protein is implicated in snRNP assembly via protein-protein interactions

Molecular and Cellular Biology ◽

10.1128/mcb.11.3.1578-1589.1991 ◽

1991 ◽

Vol 11 (3) ◽

pp. 1578-1589

Author(s):

L D Fresco ◽

D S Harper ◽

J D Keene

Keyword(s):

Protein Interactions ◽

Leucine Zipper ◽

Tandem Repeats ◽

Mutational Analysis ◽

Particle Density ◽

Protein Protein Interactions ◽

Small Nuclear Ribonucleoprotein ◽

Cell Extracts ◽

Associated Proteins ◽

Nuclear Ribonucleoprotein

Recombinant A' protein could be reconstituted into U2 small nuclear ribonucleoprotein particles (snRNPs) upon addition to HeLa cell extracts as determined by coimmunoprecipitation and particle density; however, direct binding to U2 RNA could not be demonstrated except in the presence of the U2 snRNP B" protein. Mutational analysis indicated that a central core region of A' was required for particle reconstitution. This region consists of five tandem repeats of approximately 24 amino acids each that exhibit a periodicity of leucine and asparagine residues that is distinct from the leucine zipper. Similar leucine-rich (Leu-Leu motif) repeats are characteristic of a diverse array of soluble and membrane-associated proteins from yeasts to humans but have not been reported previously to reside in nuclear proteins. Several of these proteins, including Toll, chaoptin, RNase/angiogenin inhibitors, lutropin-choriogonadotropin receptor, carboxypeptidase N, adenylyl cyclase, CD14, and human immunodeficiency virus type 1 Rev, may be involved in protein-protein interactions. Our findings suggest that in cell extracts the Leu-Leu motif of A' is required for reconstitution with U2 snRNPs and perhaps with other components involved in splicing through protein-protein interactions.

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Multi-Omics Analysis Identifying Key Biomarkers in Ovarian Cancer

Cancer Control ◽

10.1177/1073274820976671 ◽

2020 ◽

Vol 27 (1) ◽

pp. 107327482097667

Author(s):

Ju-Yueh Li ◽

Chia-Jung Li ◽

Li-Te Lin ◽

Kuan-Hao Tsui

Keyword(s):

Ovarian Cancer ◽

Protein Interactions ◽

Malignant Tumors ◽

Single Gene ◽

Protein Protein Interactions ◽

Normal Tissues ◽

Human Protein Atlas ◽

Copy Number Changes ◽

And Function ◽

Cancer Tissues

Ovarian cancer is one of the most common malignant tumors. Here, we aimed to study the expression and function of the CREB1 gene in ovarian cancer via the bioinformatic analyses of multiple databases. Previously, the prognosis of ovarian cancer was based on single-factor or single-gene studies. In this study, different bioinformatics tools (such as TCGA, GEPIA, UALCAN, MEXPRESS, and Metascape) have been used to assess the expression and prognostic value of the CREB1 gene. We used the Reactome and cBioPortal databases to identify and analyze CREB1 mutations, copy number changes, expression changes, and protein–protein interactions. By analyzing data on the CREB1 differential expression in ovarian cancer tissues and normal tissues from 12 studies collected from the “Human Protein Atlas” database, we found a significantly higher expression of CREB1 in normal ovarian tissues. Using this database, we collected information on the expression of 25 different CREB-related proteins, including TP53, AKT1, and AKT3. The enrichment of these factors depended on tumor metabolism, invasion, proliferation, and survival. Individualized tumors based on gene therapy related to prognosis have become a new possibility. In summary, we established a new type of prognostic gene profile for ovarian cancer using the tools of bioinformatics.

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In Vivo Quantitative Estimation of DNA-Dependent Interaction of Sox2 and Oct4 Using BirA-Catalyzed Site-Specific Biotinylation

Biomolecules ◽

10.3390/biom10010142 ◽

2020 ◽

Vol 10 (1) ◽

pp. 142 ◽

Cited By ~ 1

Author(s):

Arman Kulyyassov ◽

Vasily Ogryzko

Keyword(s):

Transcription Factors ◽

Protein Interactions ◽

Fluorescent Protein ◽

Quantitative Estimation ◽

Multiple Reaction Monitoring ◽

Negative Control ◽

Protein Protein Interactions ◽

Close Proximity ◽

Green Fluorescent

Protein–protein interactions of core pluripotency transcription factors play an important role during cell reprogramming. Cell identity is controlled by a trio of transcription factors: Sox2, Oct4, and Nanog. Thus, methods that help to quantify protein–protein interactions may be useful for understanding the mechanisms of pluripotency at the molecular level. Here, a detailed protocol for the detection and quantitative analysis of in vivo protein–protein proximity of Sox2 and Oct4 using the proximity-utilizing biotinylation (PUB) method is described. The method is based on the coexpression of two proteins of interest fused to a biotin acceptor peptide (BAP)in one case and a biotin ligase enzyme (BirA) in the other. The proximity between the two proteins leads to more efficient biotinylation of the BAP, which can be either detected by Western blotting or quantified using proteomics approaches, such as a multiple reaction monitoring (MRM) analysis. Coexpression of the fusion proteins BAP-X and BirA-Y revealed strong biotinylation of the target proteins when X and Y were, alternatively, the pluripotency transcription factors Sox2 and Oct4, compared with the negative control where X or Y was green fluorescent protein (GFP), which strongly suggests that Sox2 and Oct4 come in close proximity to each other and interact.

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