scholarly journals COMMD Proteins, a Novel Family of Structural and Functional Homologs of MURR1

2005 ◽  
Vol 280 (23) ◽  
pp. 22222-22232 ◽  
Author(s):  
Ezra Burstein ◽  
Jamie E. Hoberg ◽  
Amanda S. Wilkinson ◽  
Julie M. Rumble ◽  
Rebecca A. Csomos ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Protein Protein Interactions ◽  
Multifunctional Protein ◽  
New Family ◽  
The Family ◽  
Eukaryotic Organisms ◽  
Pleiotropic Functions ◽  
Cycle Regulation

MURR1 is a multifunctional protein that inhibits nuclear factor κB (NF-κB), a transcription factor with pleiotropic functions affecting innate and adaptive immunity, apoptosis, cell cycle regulation, and oncogenesis. Here we report the discovery of a new family of proteins with homology to MURR1. These proteins form multimeric complexes and were identified in a biochemical screen for MURR1-associated factors. The family is defined by the presence of a conserved and unique motif termed the COMM (copper metabolism gene MURR1) domain, which functions as an interface for protein-protein interactions. Like MURR1, several of these factors also associate with and inhibit NF-κB. The proteins designated as COMMD or COMM domain containing 1–10 are extensively conserved in multicellular eukaryotic organisms and define a novel family of structural and functional homologs of MURR1. The prototype of this family, MURR1/COMMD1, suppresses NF-κB not by affecting nuclear translocation or binding of NF-κB to cognate motifs; rather, it functions in the nucleus by affecting the association of NF-κB with chromatin.

scholarly journals Characterization of COMMD protein–protein interactions in NF-κB signalling

2006 ◽  
Vol 398 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Prim de Bie ◽  
Bart van de Sluis ◽  
Ezra Burstein ◽  
Karen J. Duran ◽  
Ruud Berger ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Copper Metabolism ◽  
Nuclear Factor Κb ◽  
Inhibitory Effect ◽  
Protein Family ◽  
Amino Acid Residues ◽  
Protein Protein Interactions ◽  
Necrosis Factor

COMMD [copper metabolism gene MURR1 (mouse U2af1-rs1 region 1) domain] proteins constitute a recently identified family of NF-κB (nuclear factor κB)-inhibiting proteins, characterized by the presence of the COMM domain. In the present paper, we report detailed investigation of the role of this protein family, and specifically the role of the COMM domain, in NF-κB signalling through characterization of protein–protein interactions involving COMMD proteins. The small ubiquitously expressed COMMD6 consists primarily of the COMM domain. Therefore COMMD1 and COMMD6 were analysed further as prototype members of the COMMD protein family. Using specific antisera, interaction between endogenous COMMD1 and COMMD6 is described. This interaction was verified by independent techniques, appeared to be direct and could be detected throughout the whole cell, including the nucleus. Both proteins inhibit TNF (tumour necrosis factor)-induced NF-κB activation in a non-synergistic manner. Mutation of the amino acid residues Trp24 and Pro41 in the COMM domain of COMMD6 completely abolished the inhibitory effect of COMMD6 on TNF-induced NF-κB activation, but this was not accompanied by loss of interaction with COMMD1, COMMD6 or the NF-κB subunit RelA. In contrast with COMMD1, COMMD6 does not bind to IκBα (inhibitory κBα), indicating that both proteins inhibit NF-κB in an overlapping, but not completely similar, manner. Taken together, these data support the significance of COMMD protein–protein interactions and provide new mechanistic insight into the function of this protein family in NF-κB signalling.

scholarly journals Crystal Structure of SEDL and Its Implications for a Genetic Disease Spondyloepiphyseal Dysplasia Tarda

2002 ◽  
Vol 277 (51) ◽  
pp. 49863-49869 ◽  
Author(s):  
Se Bok Jang ◽  
Yeon-Gil Kim ◽  
Yong-Soon Cho ◽  
Pann-Ghill Suh ◽  
Kyung-Hwa Kim ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Genetic Disease ◽  
Point Mutations ◽  
Missense Mutations ◽  
Protein Protein Interactions ◽  
Spondyloepiphyseal Dysplasia ◽  
Multiple Protein ◽  
Protein Particle ◽  
Eukaryotic Organisms ◽  
Spondyloepiphyseal Dysplasia Tarda

SEDL is an evolutionarily highly conserved protein in eukaryotic organisms. Deletions or point mutations in theSEDLgene are responsible for the genetic disease spondyloepiphyseal dysplasia tarda (SEDT), an X-linked skeletal disorder. SEDL has been identified as a component of the transport protein particle (TRAPP), critically involved in endoplasmic reticulum-to-Golgi vesicle transport. Herein, we report the 2.4 Å resolution structure of SEDL, which reveals an unexpected similarity to the structures of the N-terminal regulatory domain of two SNAREs, Ykt6p and Sec22b, despite no sequence homology to these proteins. The similarity and the presence of unusually many solvent-exposed apolar residues of SEDL suggest that it serves regulatory and/or adaptor functions through multiple protein-protein interactions. Of the four known missense mutations responsible for SEDT, three mutations (S73L, F83S, V130D) map to the protein interior, where the mutations would disrupt the structure, and the fourth (D47Y) on a surface at which the mutation may abrogate functional interactions with a partner protein.

scholarly journals Selective Affimers Recognize BCL-2 Family Proteins Through Non-Canonical Structural Motifs

2019 ◽  
Author(s):  
Jennifer A. Miles ◽  
Fruzsina Hobor ◽  
James Taylor ◽  
Christian Tiede ◽  
Philip R. Rowell ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Cell Biology ◽  
Competitive Inhibition ◽  
Antibody Binding ◽  
Proof Of Concept ◽  
Protein Protein Interactions ◽  
The Family ◽  
Selective Ligands ◽  
Binding Cleft ◽  
Characterisation Methods

AbstractThe BCL-2 family is a challenging set of proteins to target selectively due to sequence and structural homologies across the family. Selective ligands for the BCL-2 family regulators of apoptosis are desirable as probes to understand cell biology and apoptotic signalling pathways, and as starting points for inhibitor design. We have used phage display to isolate Affimer reagents (non-antibody binding proteins based on a conserved scaffold) to identify ligands for MCL-1, BCL-xL, BCL-2, BAK and BAX, then used multiple biophysical characterisation methods to probe the interactions. We established that purified Affimers elicit selective and potent recognition of their target BCL-2 protein. For anti-apoptotic targets, competitive inhibition of their canonical protein-protein interactions is demonstrated. Co-crystal structures reveal an unprecedented mode of molecular recognition; where a BH3 helix is normally bound, flexible loops from the Affimer dock into the BH3 binding cleft. Moreover, the Affimers induce a change in the target proteins towards a desirable drug bound like conformation. These results indicate Affimers can be used as alternative templates to inspire design of selective BCL-2 family modulators, and provide proof-of-concept for the elaboration of selective non-antibody binding reagents for use in cell-biology applications.

scholarly journals Stat5b Inhibits NFκB-Mediated Signaling

2000 ◽  
Vol 14 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Guoyang Luo ◽  
Li-yuan Yu-Lee
Keyword(s):  
Protein Interactions ◽  
Nuclear Translocation ◽  
Early Response ◽  
Inhibitory Effect ◽  
Interferon Regulatory Factor ◽  
Cytokine Signaling ◽  
Regulatory Factor ◽  
Protein Protein Interactions ◽  
Interferon Regulatory Factor 1 ◽  
Target Promoters

Abstract Signal transducers and activators of transcription (Stat) are latent transcription factors that participate in cytokine signaling by regulating the expression of early response genes. Our previous studies showed that Stat5 functions not only as a transcriptional activator but also as a transcriptional inhibitor, depending on the target promoter. This report further investigates the mechanism of Stat5b-mediated inhibition and demonstrates that PRL-inducible Stat5b inhibits nuclear factorκB (NFκB) signaling to both the interferon regulatory factor-1 promoter and to the thymidine kinase promoter containing multimerized NFκB elements (NFκB-TK). Further, PRL-inducible Stat5b inhibits tumor necrosis factor-α signaling presumably by inhibiting endogenous NFκB. This Stat5b-mediated inhibitory effect on NFκB signaling is independent of Stat5b-DNA interactions but requires the carboxyl terminus of Stat5b as well as Stat5b nuclear translocation and/or accumulation, suggesting that Stat5b is competing for a nuclear factor(s) necessary for NFκB-mediated activation of target promoters. Increasing concentrations of the coactivator p300/CBP reverses Stat5b inhibition at both the interferon-regulatory factor-1 and NFκB-TK promoters, suggesting that Stat5b may be squelching limiting coactivators via protein-protein interactions as one mechanism of promoter inhibition. These results further substantiate our observation that Stat factors can function as transcriptional inhibitors. Our studies reveal cross-talk between the Stat5b and NFκB signal transduction pathways and suggest that Stat5b-mediated inhibition of target promoters occurs at the level of protein-protein interactions and involves competition for limiting coactivators.

Modulating the Bcl-2 Family of Apoptosis Suppressors for Potential Therapeutic Benefit in Cancer

Hematology ◽  
2005 ◽  
Vol 2005 (1) ◽  
pp. 226-230 ◽  
Author(s):  
Gordon C. Shore ◽  
Jean Viallet
Keyword(s):  
Protein Interactions ◽  
Therapeutic Benefit ◽  
Protein Protein Interactions ◽  
Cancer Treatments ◽  
The Family ◽  
Challenges And Opportunities ◽  
Apoptosis Pathways ◽  
Current Therapies ◽  
Cellular Oncogenes ◽  
Potential Therapeutic Benefit

Abstract Members of the BCL-2 family of proteins regulate and execute many cell intrinsic apoptosis pathways, including those arising from dysregulated expression of cellular oncogenes. Since pro-survival members of the family are often strongly elevated in diverse cancers, with the potential to confer resistance to both endogenous cell death stimuli and many cancer treatments, there has been intense interest to develop strategies to therapeutically modulate their activity. Although encouraging genetic and pharmacological preclinical proof of concept has been obtained, the challenge for clinical development will be to devise strategies that address the fact that multiple pro-survival members are typically up-regulated in a given cancer and the family operates primarily through protein-protein interactions. Moreover, since several current therapies themselves are known to stimulate the levels of one or more family members, there will be additional challenges (and opportunities) in exploiting this target in the clinic. In this review, we describe the rationale for targeting the BCL-2 family of apoptosis suppressors in cancer and the progress that has been made in modulating the family by small molecule antagonists.

scholarly journals Design and Prototyping of Genetically Encoded Arsenic Biosensors Based on Transcriptional Regulator AfArsR

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1276
Author(s):  
Salma Saeed Khan ◽  
Yi Shen ◽  
Muhammad Qaiser Fatmi ◽  
Robert E. Campbell ◽  
Habib Bokhari
Keyword(s):  
Protein Interactions ◽  
Protein Function ◽  
Fluorescent Proteins ◽  
Transcriptional Factor ◽  
Thiol Groups ◽  
Protein Protein Interactions ◽  
Protein Thiol ◽  
New Family

Genetically encoded biosensors based on engineered fluorescent proteins (FPs) are essential tools for monitoring the dynamics of specific ions and molecules in biological systems. Arsenic ion in the +3 oxidation state (As3+) is highly toxic to cells due to its ability to bind to protein thiol groups, leading to inhibition of protein function, disruption of protein–protein interactions, and eventually to cell death. A genetically encoded biosensor for the detection of As3+ could potentially facilitate the investigation of such toxicity both in vitro and in vivo. Here, we designed and developed two prototype genetically encoded arsenic biosensors (GEARs), based on a bacterial As3+ responsive transcriptional factor AfArsR from Acidithiobacillus ferrooxidans. We constructed FRET-based GEAR biosensors by insertion of AfArsR between FP acceptor/donor FRET pairs. We further designed and engineered single FP-based GEAR biosensors by insertion of AfArsR into GFP. These constructs represent prototypes for a new family of biosensors based on the ArsR transcriptional factor scaffold. Further improvements of the GEAR biosensor family could lead to variants with suitable performance for detection of As3+ in various biological and environmental systems.

scholarly journals ZNF224 Protein: Multifaceted Functions Based on Its Molecular Partners

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6296
Author(s):  
Elena Cesaro ◽  
Angelo Lupo ◽  
Roberta Rapuano ◽  
Arianna Pastore ◽  
Michela Grosso ◽  
...  
Keyword(s):  
Dna Binding ◽  
Zinc Finger ◽  
Protein Interactions ◽  
Transcriptional Repression ◽  
Zinc Finger Protein ◽  
Current Knowledge ◽  
Protein Protein Interactions ◽  
Multifunctional Protein ◽  
Finger Protein ◽  
Zinc Finger Domains

The transcription factor ZNF224 is a Kruppel-like zinc finger protein that consists of 707 amino acids and contains 19 tandemly repeated C2H2 zinc finger domains that mediate DNA binding and protein–protein interactions. ZNF224 was originally identified as a transcriptional repressor of genes involved in energy metabolism, and it was demonstrated that ZNF224-mediated transcriptional repression needs the interaction of its KRAB repressor domain with the co-repressor KAP1 and its zinc finger domains 1–3 with the arginine methyltransferase PRMT5. Furthermore, the protein ZNF255 was identified as an alternative isoform of ZNF224 that possesses different domain compositions mediating distinctive functional interactions. Subsequent studies showed that ZNF224 is a multifunctional protein able to exert different transcriptional activities depending on the cell context and the variety of its molecular partners. Indeed, it has been shown that ZNF224 can act as a repressor, an activator and a cofactor for other DNA-binding transcription factors in different human cancers. Here, we provide a brief overview of the current knowledge on the multifaceted interactions of ZNF224 and the resulting different roles of this protein in various cellular contexts.

scholarly journals The E3 ubiquitin-protein ligase MDM2 is a novel interactor of the von Hippel-Lindau tumor suppressor

2020 ◽  
Author(s):  
Antonella Falconieri ◽  
Giovanni Minervini ◽  
Raissa Bortolotto ◽  
Damiano Piovesan ◽  
Raffaele Lopreiato ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Protein Interactions ◽  
Hypoxia Inducible Factor ◽  
Protein Protein Interactions ◽  
Von Hippel Lindau ◽  
Intrinsically Disordered ◽  
Tetramerization Domain ◽  
Specific Association ◽  
Cycle Regulation

AbstractMutations of the von Hippel-Lindau (pVHL) tumor suppressor are causative of a familiar predisposition to develop different types of cancer. pVHL is mainly known for its role in regulating hypoxia-inducible factor 1-α (HIF-1α) degradation, thus modulating the hypoxia response. There are different pVHL isoforms, including pVHL30 and pVHL19. However, little is known about isoform-specific functions and protein-protein interactions. Integrating in silico predictions with in vitro and in vivo assays, we describe a novel interaction between pVHL and mouse double minute 2 homolog (MDM2). Importantly, we found that pVHL30, and not pVHL19, forms a complex with MDM2, and that the N-terminal acidic tail of pVHL30 is required for its association with MDM2. Further, we demonstrate that an intrinsically disordered region upstream of the tetramerization domain of MDM2 is responsible for its isoform-specific association with pVHL30. This region is highly conserved in higher mammals, including primates, similarly to what has been already proposed for the N-terminal tail of pVHL30. Finally, we show that overexpression of pVHL30 and MDM2 together reduces cell proliferation, suggesting a synergistic effect of these E3 ubiquitin ligases. Collectively, our data support the idea that pVHL30 plays a role in MDM2 regulation, suggesting a wider interplay among hypoxia sensing and cell cycle regulation.

scholarly journals The interaction of verprolin WIRE with the adapter proteins family intersectin

2019 ◽  
Vol 17 (1) ◽  
pp. 3-7
Author(s):  
S. V. Kropyvko ◽  
A. V. Rynditch
Keyword(s):  
Actin Cytoskeleton ◽  
Protein Interactions ◽  
Adapter Proteins ◽  
Protein Protein Interactions ◽  
Sh3 Domains ◽  
Invasion And Migration ◽  
The Family ◽  
Cellular Signal ◽  
And Migration ◽  
Cytoskeleton Rearrangements

Aim. WIRE is a scafold protein that regulates actin cytoskeleton rearrangements and the formation of actin enriched membrane processes responsible for invasion and migration. ITSN1 and ITSN2 are representatives of the family of intersectins who participate in the reorganization of the actin cytoskeleton, as well as in other processes, such as endo/enzocytosis, cellular signal transduction, etc. As these proteins participate in the same processes, we checked their interaction with each other. Methods. Protein-protein interactions were identified using the GST pull-down method. Results. We showed that the SH3 domains of ITSN1 and ITSN2 interact with WIRE, and found that while WIRE is in a complex with endogenous actin. Conclusions. ITSN1 and ITSN2 interact with WIRE, which is located in a complex with endogenous actin. Keywords: WIRE, ITSN1 and ITSN2, actin.

scholarly journals Regulation of Autophagy by Nuclear GAPDH and Its Aggregates in Cancer and Neurodegenerative Disorders

2019 ◽  
Vol 20 (9) ◽  
pp. 2062 ◽  
Author(s):  
Giovanna Butera ◽  
Nidula Mullappilly ◽  
Francesca Masetto ◽  
Marta Palmieri ◽  
Maria Teresa Scupoli ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Interactions ◽  
Neurodegenerative Disorders ◽  
Therapeutic Target ◽  
Molecular Mechanisms ◽  
Amino Acid Residues ◽  
Protein Protein Interactions ◽  
Cellular Effects ◽  
Rna Export ◽  
Pleiotropic Functions

Several studies indicate that the cytosolic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has pleiotropic functions independent of its canonical role in glycolysis. The GAPDH functional diversity is mainly due to post-translational modifications in different amino acid residues or due to protein–protein interactions altering its localization from cytosol to nucleus, mitochondria or extracellular microenvironment. Non-glycolytic functions of GAPDH include the regulation of cell death, autophagy, DNA repair and RNA export, and they are observed in physiological and pathological conditions as cancer and neurodegenerative disorders. In disease, the knowledge of the mechanisms regarding GAPDH-mediated cell death is becoming fundamental for the identification of novel therapies. Here, we elucidate the correlation between autophagy and GAPDH in cancer, describing the molecular mechanisms involved and its impact in cancer development. Since autophagy is a degradative pathway associated with the regulation of cell death, we discuss recent evidence supporting GAPDH as a therapeutic target for autophagy regulation in cancer therapy. Furthermore, we summarize the molecular mechanisms and the cellular effects of GAPDH aggregates, which are correlated with mitochondrial malfunctions and can be considered a potential therapeutic target for various diseases, including cancer and neurodegenerative disorders.

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