scholarly journals Structure and function of steroid receptor AF1 transactivation domains: induction of active conformations

2005 ◽  
Vol 391 (3) ◽  
pp. 449-464 ◽  
Author(s):  
Derek N. Lavery ◽  
Iain J. Mcewan
Keyword(s):  
Protein Interactions ◽  
Functional Model ◽  
Binding Domain ◽  
Protein Protein Interactions ◽  
Receptor Proteins ◽  
Signalling Molecules ◽  
Transactivation Domains ◽  
Induced Folding ◽  
Α Helix ◽  
And Function

Steroid hormones are important endocrine signalling molecules controlling reproduction, development, metabolism, salt balance and specialized cellular responses, such as inflammation and immunity. They are lipophilic in character and act by binding to intracellular receptor proteins. These receptors function as ligand-activated transcription factors, switching on or off networks of genes in response to a specific hormone signal. The receptor proteins have a conserved domain organization, comprising a C-terminal LBD (ligand-binding domain), a hinge region, a central DBD (DNA-binding domain) and a highly variable NTD (N-terminal domain). The NTD is structurally flexible and contains surfaces for both activation and repression of gene transcription, and the strength of the transactivation response has been correlated with protein length. Recent evidence supports a structural and functional model for the NTD that involves induced folding, possibly involving α-helix structure, in response to protein–protein interactions and structure-stabilizing solutes.

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

2003 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
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.

scholarly journals Peptide-based inhibitors of protein–protein interactions: biophysical, structural and cellular consequences of introducing a constraint

2021 ◽  
Author(s):  
Hongshuang Wang ◽  
Robert S. Dawber ◽  
Peiyu Zhang ◽  
Martin Walko ◽  
Andrew J. Wilson ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Α Helix ◽  
Cellular Behaviour

This review summarizes the influence of inserting constraints on biophysical, conformational, structural and cellular behaviour for peptides targeting α-helix mediated protein–protein interactions.

scholarly journals Interactions between Integrase and Excisionase in the Phage Lambda Excisive Nucleoprotein Complex

2002 ◽  
Vol 184 (18) ◽  
pp. 5200-5203 ◽  
Author(s):  
Eun Hee Cho ◽  
Richard I. Gumport ◽  
Jeffrey F. Gardner
Keyword(s):  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Mobility Shift ◽  
Host Chromosome ◽  
Amino Terminal ◽  
Nucleoprotein Complex ◽  
Carboxyl Terminal ◽  
Α Helix ◽  
Gel Mobility Shift ◽  
Amino Terminal Domain

ABSTRACT Bacteriophage lambda site-specific recombination comprises two overall reactions, integration into and excision from the host chromosome. Lambda integrase (Int) carries out both reactions. During excision, excisionase (Xis) helps Int to bind DNA and introduces a bend in the DNA that facilitates formation of the proper excisive nucleoprotein complex. The carboxyl-terminal α-helix of Xis is thought to interact with Int through direct protein-protein interactions. In this study, we used gel mobility shift assays to show that the amino-terminal domain of Int maintained cooperative interactions with Xis. This finding indicates that the amino-terminal arm-type DNA binding domain of Int interacts with Xis.

scholarly journals Optimal Anchoring of a Urea-based Foldamer Inhibitor of ASF1 Histone Chaperone Through Backbone Plasticity

2020 ◽  
Author(s):  
Johanne Mbianda ◽  
May Bakail ◽  
Christophe André ◽  
Gwenaëlle Moal ◽  
Marie E. Perrin ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Histone Chaperone ◽  
Protein Protein Interactions ◽  
Protein Surface ◽  
Chromatin Dynamics ◽  
Correct Orientation ◽  
Surface Recognition ◽  
Binding Interface ◽  
Helical Peptide ◽  
Α Helix

<p><b>Sequence-specific oligomers with predictable folding patterns, i.e. foldamers provide new opportunities to mimic α-helical peptides and design inhibitors of protein-protein interactions. One major hurdle of this strategy is to retain the correct orientation of key side chains involved in protein surface recognition. Here, we show that the structural plasticity of a foldamer backbone may significantly contribute to the required spatial adjustment for optimal interaction with the protein surface. By using oligoureas as α-helix mimics, we designed a foldamer/peptide hybrid inhibitor of histone chaperone ASF1, a key regulator of chromatin dynamics. The crystal structure of its complex with ASF1 reveals a striking plasticity of the urea backbone, which adapts to the ASF1 surface to maintain the same binding interface. One additional benefit of generating ASF1 ligands with non-peptide oligourea segments is the resistance to proteolysis in human plasma which was highly improved compared to the cognate α-helical peptide. </b></p>

scholarly journals Correction to α-Helix-Mimicking Sulfono-γ-AApeptide Inhibitors for p53–MDM2/MDMX Protein–Protein Interactions

2020 ◽  
Vol 63 (17) ◽  
pp. 10087-10087
Author(s):  
Peng Sang ◽  
Yan Shi ◽  
Junhao Lu ◽  
Lihong Chen ◽  
Leixiang Yang ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Α Helix

scholarly journals Multi-Omics Analysis Identifying Key Biomarkers in Ovarian Cancer

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.

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

Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 2920-2932 ◽  
Author(s):  
Goran Jovanovic ◽  
Christoph Engl ◽  
Antony J. Mayhew ◽  
Patricia C. Burrows ◽  
Martin Buck
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Protein Interactions ◽  
Leucine Zipper ◽  
Negative Control ◽  
Stress Conditions ◽  
Bacterial Cells ◽  
Protein Protein Interactions ◽  
Regulatory Complex ◽  
And Function

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.

scholarly journals Distinct activities of Scrib module proteins organize epithelial polarity

2020 ◽  
Vol 117 (21) ◽  
pp. 11531-11540 ◽  
Author(s):  
Mark J. Khoury ◽  
David Bilder
Keyword(s):  
Protein Interactions ◽  
Molecular Mechanisms ◽  
Epithelial Polarity ◽  
Protein Protein Interactions ◽  
Kinase C ◽  
Mutual Antagonism ◽  
Discs Large ◽  
Lethal Giant Larvae ◽  
Epithelial Structure ◽  
And Function

A polarized architecture is central to both epithelial structure and function. In many cells, polarity involves mutual antagonism between the Par complex and the Scribble (Scrib) module. While molecular mechanisms underlying Par-mediated apical determination are well-understood, how Scrib module proteins specify the basolateral domain remains unknown. Here, we demonstrate dependent and independent activities of Scrib, Discs-large (Dlg), and Lethal giant larvae (Lgl) using theDrosophilafollicle epithelium. Our data support a linear hierarchy for localization, but rule out previously proposed protein–protein interactions as essential for polarization. Cortical recruitment of Scrib does not require palmitoylation or polar phospholipid binding but instead an independent cortically stabilizing activity of Dlg. Scrib and Dlg do not directly antagonize atypical protein kinase C (aPKC), but may instead restrict aPKC localization by enabling the aPKC-inhibiting activity of Lgl. Importantly, while Scrib, Dlg, and Lgl are each required, all three together are not sufficient to antagonize the Par complex. Our data demonstrate previously unappreciated diversity of function within the Scrib module and begin to define the elusive molecular functions of Scrib and Dlg.

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