scholarly journals Identification of the Repressive Domain of the Negative Circadian Clock Component CHRONO

2019 ◽  
Author(s):  
Yu Yang ◽  
Ning Li ◽  
Jiameng Qiu ◽  
Honghua Ge ◽  
Ximing Qin
Keyword(s):  
Protein Interactions ◽  
Transcriptional Activity ◽  
Structural Information ◽  
Luciferase Reporter ◽  
Circadian Cycle ◽  
Information Analysis ◽  
Protein Protein Interactions ◽  
C Terminus ◽  
Clock Component ◽  
Reporter Assays

AbstractCircadian rhythm is an endogenous, self-sustainable oscillation that participates in regulating organisms’ physiological activities. Key to this oscillation is a negative feedback by main clock components Periods and Cryptochromes that repress transcriptional activity of BMAL1/CLOCK complexes. In addition, a novel repressor, CHRONO, has been identified recently, but details of CHRONO’s function during repressing the circadian cycle remain unclear. Here we report that a domain of CHRONO mainly composed of α-helixes is critical to repression through the exploitation of protein-protein interactions according to luciferase reporter assays, co-immunoprecipitation, immunofluorescence, genome editing and structural information analysis via circular dichroism spectroscopy. This repression is fulfilled by interactions between CHRONO with a region on the BMAL1 C-terminus where Cryptochrome and CBP bind. Our results indicate that CHRONO and PER differentially function as BMALA/CLOCK-dependent repressors. We further suggest a repression model of how PER, CRY and CHRONO proteins associate with BMAL1, respectively.

scholarly journals Identification of the Repressive Domain of the Negative Circadian Clock Component CHRONO

2020 ◽  
Vol 21 (7) ◽  
pp. 2469
Author(s):  
Yu Yang ◽  
Ning Li ◽  
Jiameng Qiu ◽  
Honghua Ge ◽  
Ximing Qin
Keyword(s):  
Protein Interactions ◽  
Transcriptional Activity ◽  
Structural Information ◽  
Luciferase Reporter ◽  
Circadian Cycle ◽  
Information Analysis ◽  
Protein Protein Interactions ◽  
C Terminus ◽  
Clock Component ◽  
Reporter Assays

Circadian rhythm is an endogenous, self-sustainable oscillation that participates in regulating organisms’ physiological activities. Key to this oscillation is a negative feedback by the main clock components Periods and Cryptochromes that repress the transcriptional activity of BMAL1/CLOCK (defined in the Abbreviations) complexes. In addition, a novel repressor, CHRONO, has been identified recently, but details of CHRONO’s function during repressing the circadian cycle remain unclear. Here we report that a domain of CHRONO mainly composed of α-helixes is critical to repression through the exploitation of protein–protein interactions according to luciferase reporter assays, co-immunoprecipitation, immunofluorescence, genome editing, and structural information analysis via circular dichroism spectroscopy. This repression is fulfilled by interactions between CHRONO and a region on the C-terminus of BMAL1 where Cryptochrome and CBP (defined in the Abbreviations) bind. Our resultsindicate that CHRONO and PER differentially function as BMAL1/CLOCK-dependent repressors. Besides, the N-terminus of CHRONO is important for its nuclear localization. We further develop a repression model of how PER, CRY, and CHRONO proteins associate with BMAL1, respectively.

scholarly journals Association Between Functional PSMD10 Rs111638916 Variant Regulated by MiR-505 and Gastric Cancer Risk in a Chinese Population

2015 ◽  
Vol 37 (3) ◽  
pp. 1010-1017 ◽  
Author(s):  
Yong Liu ◽  
Jianzhong Xu ◽  
Min Jiang ◽  
Lingna Ni ◽  
Yun Chen ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Protein Interactions ◽  
Micro Rna ◽  
Chinese Patients ◽  
Luciferase Reporter ◽  
Nucleotide Polymorphisms ◽  
Protein Protein Interactions ◽  
Reaction Cell ◽  
Increased Risk ◽  
Reporter Assays

Background/Aims: Gankyrin is an oncoprotein involved in regulating the cell cycle through protein-protein interactions with cyclin-dependent kinase 4 and p53. However, its association with gastric cancer (GC) risk has not yet been determined. In this study, we investigated micro RNA (miRNA)-associated single nucleotide polymorphisms (SNPs) in the 3′-untranslated region (UTR) of the gankyrin gene PSMD10 to clarify the relationship between these SNPs and miRNAs in Chinese patients with GC. Methods: We performed a case-control study including 857 GC patients and 748 cancer-free controls. PSMD10 expression was investigated using genotyping, real-time polymerase chain reaction, cell transfection, and dual luciferase reporter assays. Results: Patients with histories of smoking, alcohol consumption, and cancer were more susceptible to GC than controls. The SNP rs111638916 in the PSMD10 3′-UTR was identified as a risk factor for GC and acted as a tumor promoting factor. SNP rs111638916 was also regulated by miR-505, resulting in up-regulation of gankyrin expression in patients with GA and AA genotypes. Carriers of the GA and AA genotypes also presented with larger tumors and had a higher risk of metastasis. Conclusion: The PSMD10 rs111638916 SNP is highly associated with an increased risk of GC in Chinese patients, and could serve as a novel biomarker for this disease.

Protein Interaction Domains and Post-Translational Modifications: Structural Features and Drug Discovery Applications

2020 ◽  
Vol 27 (37) ◽  
pp. 6306-6355 ◽  
Author(s):  
Marian Vincenzi ◽  
Flavia Anna Mercurio ◽  
Marilisa Leone
Keyword(s):  
Drug Discovery ◽  
Protein Interaction ◽  
Protein Interactions ◽  
Structural Information ◽  
Protein Complexes ◽  
Structural Features ◽  
Protein Protein Interactions ◽  
Modular Architecture ◽  
Post Translational Modifications ◽  
Interaction Domains

Background:: Many pathways regarding healthy cells and/or linked to diseases onset and progression depend on large assemblies including multi-protein complexes. Protein-protein interactions may occur through a vast array of modules known as protein interaction domains (PIDs). Objective:: This review concerns with PIDs recognizing post-translationally modified peptide sequences and intends to provide the scientific community with state of art knowledge on their 3D structures, binding topologies and potential applications in the drug discovery field. Method:: Several databases, such as the Pfam (Protein family), the SMART (Simple Modular Architecture Research Tool) and the PDB (Protein Data Bank), were searched to look for different domain families and gain structural information on protein complexes in which particular PIDs are involved. Recent literature on PIDs and related drug discovery campaigns was retrieved through Pubmed and analyzed. Results and Conclusion:: PIDs are rather versatile as concerning their binding preferences. Many of them recognize specifically only determined amino acid stretches with post-translational modifications, a few others are able to interact with several post-translationally modified sequences or with unmodified ones. Many PIDs can be linked to different diseases including cancer. The tremendous amount of available structural data led to the structure-based design of several molecules targeting protein-protein interactions mediated by PIDs, including peptides, peptidomimetics and small compounds. More studies are needed to fully role out, among different families, PIDs that can be considered reliable therapeutic targets, however, attacking PIDs rather than catalytic domains of a particular protein may represent a route to obtain selective inhibitors.

scholarly journals E. coli primase and DNA polymerase III holoenzyme are able to bind concurrently to a primed template during DNA replication

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea Bogutzki ◽  
Natalie Naue ◽  
Lidia Litz ◽  
Andreas Pich ◽  
Ute Curth
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
Protein Interactions ◽  
Dna Polymerase Iii ◽  
Protein Protein Interactions ◽  
Single Stranded Dna ◽  
E Coli ◽  
Polymerase Iii ◽  
C Terminus ◽  
Pol Iii

Abstract During DNA replication in E. coli, a switch between DnaG primase and DNA polymerase III holoenzyme (pol III) activities has to occur every time when the synthesis of a new Okazaki fragment starts. As both primase and the χ subunit of pol III interact with the highly conserved C-terminus of single-stranded DNA-binding protein (SSB), it had been proposed that the binding of both proteins to SSB is mutually exclusive. Using a replication system containing the origin of replication of the single-stranded DNA phage G4 (G4ori) saturated with SSB, we tested whether DnaG and pol III can bind concurrently to the primed template. We found that the addition of pol III does not lead to a displacement of primase, but to the formation of higher complexes. Even pol III-mediated primer elongation by one or several DNA nucleotides does not result in the dissociation of DnaG. About 10 nucleotides have to be added in order to displace one of the two primase molecules bound to SSB-saturated G4ori. The concurrent binding of primase and pol III is highly plausible, since even the SSB tetramer situated directly next to the 3′-terminus of the primer provides four C-termini for protein-protein interactions.

scholarly journals Trifunctional cross-linker for mapping protein-protein interaction networks and comparing protein conformational states

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Dan Tan ◽  
Qiang Li ◽  
Mei-Jun Zhang ◽  
Chao Liu ◽  
Chengying Ma ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Structural Information ◽  
Affinity Purification ◽  
Protein Protein Interactions ◽  
C Elegans ◽  
Protein Protein Interaction ◽  
Lysine Residues ◽  
Spacer Arm ◽  
Cross Linker ◽  
Protein Nucleic Acid

To improve chemical cross-linking of proteins coupled with mass spectrometry (CXMS), we developed a lysine-targeted enrichable cross-linker containing a biotin tag for affinity purification, a chemical cleavage site to separate cross-linked peptides away from biotin after enrichment, and a spacer arm that can be labeled with stable isotopes for quantitation. By locating the flexible proteins on the surface of 70S ribosome, we show that this trifunctional cross-linker is effective at attaining structural information not easily attainable by crystallography and electron microscopy. From a crude Rrp46 immunoprecipitate, it helped identify two direct binding partners of Rrp46 and 15 protein-protein interactions (PPIs) among the co-immunoprecipitated exosome subunits. Applying it to E. coli and C. elegans lysates, we identified 3130 and 893 inter-linked lysine pairs, representing 677 and 121 PPIs. Using a quantitative CXMS workflow we demonstrate that it can reveal changes in the reactivity of lysine residues due to protein-nucleic acid interaction.

scholarly journals Activation and assembly of the NADPH oxidase: a structural perspective

2005 ◽  
Vol 386 (3) ◽  
pp. 401-416 ◽  
Author(s):  
Yvonne GROEMPING ◽  
Katrin RITTINGER
Keyword(s):  
Nadph Oxidase ◽  
Protein Interactions ◽  
Structural Information ◽  
Three Dimensional ◽  
Protein Protein Interactions ◽  
Crucial Component ◽  
Enzyme Subunits ◽  
Membrane Components ◽  
Inhibitory Interactions ◽  
Encompassing Model

The NADPH oxidase of professional phagocytes is a crucial component of the innate immune response due to its fundamental role in the production of reactive oxygen species that act as powerful microbicidal agents. The activity of this multi-protein enzyme is dependent on the regulated assembly of the six enzyme subunits at the membrane where oxygen is reduced to superoxide anions. In the resting state, four of the enzyme subunits are maintained in the cytosol, either through auto-inhibitory interactions or through complex formation with accessory proteins that are not part of the active enzyme complex. Multiple inputs are required to disrupt these inhibitory interactions and allow translocation to the membrane and association with the integral membrane components. Protein interaction modules are key regulators of NADPH oxidase assembly, and the protein–protein interactions mediated via these domains have been the target of numerous studies. Many models have been put forward to describe the intricate network of reversible protein interactions that regulate the activity of this enzyme, but an all-encompassing model has so far been elusive. An important step towards an understanding of the molecular basis of NADPH oxidase assembly and activity has been the recent solution of the three-dimensional structures of some of the oxidase components. We will discuss these structures in the present review and attempt to reconcile some of the conflicting models on the basis of the structural information available.

scholarly journals ArabidopsisImmunophilin-like TWD1 Functionally Interacts with Vacuolar ABC Transporters

2004 ◽  
Vol 15 (7) ◽  
pp. 3393-3405 ◽  
Author(s):  
Markus Geisler ◽  
Marjolaine Girin ◽  
Sabine Brandt ◽  
Vincent Vincenzetti ◽  
Sonia Plaza ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Abc Transporters ◽  
Loss Of Function ◽  
Protein Protein Interactions ◽  
Binding Motifs ◽  
Calmodulin Binding ◽  
C Terminus ◽  
Domain Mapping ◽  
Tetratricopeptide Repeat Domain

Previously, the immunophilin-like protein TWD1 from Arabidopsis has been demonstrated to interact with the ABC transporters AtPGP1 and its closest homologue, AtPGP19. Physiological and biochemical investigation of pgp1/pgp19 and of twd1 plants suggested a regulatory role of TWD1 on AtPGP1/AtPGP19 transport activities. To further understand the dramatic pleiotropic phenotype that is caused by loss-of-function mutation of the TWD1 gene, we were interested in other TWD1 interacting proteins. AtMRP1, a multidrug resistance-associated (MRP/ABCC)-like ABC transporter, has been isolated in a yeast two-hybrid screen. We demonstrate molecular interaction between TWD1 and ABC transporters AtMRP1 and its closest homologue, AtMRP2. Unlike AtPGP1, AtMRP1 binds to the C-terminal tetratricopeptide repeat domain of TWD1, which is well known to mediate protein-protein interactions. Domain mapping proved that TWD1 binds to a motif of AtMRP1 that resembles calmodulin-binding motifs; and calmodulin binding to the C-terminus of MRP1 was verified. By membrane fractionation and GFP-tagging, we localized AtMRP1 to the central vacuolar membrane and the TWD1-AtMRP1 complex was verified in vivo by coimmunoprecipitation. We were able to demonstrate that TWD1 binds to isolated vacuoles and has a significant impact on the uptake of metolachlor-GS and estradiol-β-glucuronide, well-known substrates of vacuolar transporters AtMRP1 and AtMRP2.

scholarly journals Integrating Structural Information to Study the Dynamics of Protein-Protein Interactions in Cells

Structure ◽  
2018 ◽  
Vol 26 (10) ◽  
pp. 1414-1424.e3 ◽  
Author(s):  
Bo Wang ◽  
Zhong-Ru Xie ◽  
Jiawen Chen ◽  
Yinghao Wu
Keyword(s):  
Protein Interactions ◽  
Structural Information ◽  
Protein Protein Interactions ◽  
In Cells

scholarly journals Aspartic Acid Isomerization Characterized by High Definition Mass Spectrometry Significantly Alters the Bioactivity of a Novel Toxin from Poecilotheria

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 207 ◽  
Author(s):  
Stephen R. Johnson ◽  
Hillary G. Rikli
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Ion Mobility ◽  
Protein Protein Interactions ◽  
High Definition ◽  
Vast Number ◽  
Post Translational Modifications ◽  
C Terminus ◽  
Acid Isomerization

Research in toxinology has created a pharmacological paradox. With an estimated 220,000 venomous animals worldwide, the study of peptidyl toxins provides a vast number of effector molecules. However, due to the complexity of the protein-protein interactions, there are fewer than ten venom-derived molecules on the market. Structural characterization and identification of post-translational modifications are essential to develop biological lead structures into pharmaceuticals. Utilizing advancements in mass spectrometry, we have created a high definition approach that fuses conventional high-resolution MS-MS with ion mobility spectrometry (HDMSE) to elucidate these primary structure characteristics. We investigated venom from ten species of “tiger” spider (Genus: Poecilotheria) and discovered they contain isobaric conformers originating from non-enzymatic Asp isomerization. One conformer pair conserved in five of ten species examined, denominated PcaTX-1a and PcaTX-1b, was found to be a 36-residue peptide with a cysteine knot, an amidated C-terminus, and isoAsp33Asp substitution. Although the isomerization of Asp has been implicated in many pathologies, this is the first characterization of Asp isomerization in a toxin and demonstrates the isomerized product’s diminished physiological effects. This study establishes the value of a HDMSE approach to toxin screening and characterization.

scholarly journals Protein Dynamics in F-like Bacterial Conjugation

Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 362
Author(s):  
Nicholas Bragagnolo ◽  
Christina Rodriguez ◽  
Naveed Samari-Kermani ◽  
Alice Fours ◽  
Mahboubeh Korouzhdehi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Protein Interactions ◽  
Drug Targets ◽  
Dynamic Models ◽  
Structural Information ◽  
Imaging Techniques ◽  
Antibiotic Resistance Genes ◽  
Protein Protein Interactions ◽  
Secretion Systems ◽  
Type Iv

Efficient in silico development of novel antibiotics requires high-resolution, dynamic models of drug targets. As conjugation is considered the prominent contributor to the spread of antibiotic resistance genes, targeted drug design to disrupt vital components of conjugative systems has been proposed to lessen the proliferation of bacterial antibiotic resistance. Advancements in structural imaging techniques of large macromolecular complexes has accelerated the discovery of novel protein-protein interactions in bacterial type IV secretion systems (T4SS). The known structural information regarding the F-like T4SS components and complexes has been summarized in the following review, revealing a complex network of protein-protein interactions involving domains with varying degrees of disorder. Structural predictions were performed to provide insight on the dynamicity of proteins within the F plasmid conjugative system that lack structural information.

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