scholarly journals Chimeric GPCRs mimic distinct signaling pathways and modulate microglia responses

2021 ◽  
Author(s):  
Rouven Schulz ◽  
Medina Korkut-Demirbaş ◽  
Gloria Colombo ◽  
Sandra Siegert
Keyword(s):  
Signaling Pathways ◽  
Protein Interactions ◽  
Immune Cell ◽  
Signal Transmission ◽  
The Body ◽  
Cell Type ◽  
Protein Protein Interactions ◽  
Β2 Adrenergic Receptor ◽  
Neuronal Signal ◽  
And Function

G protein-coupled receptors (GPCRs) regulate multiple processes ranging from cell growth and immune responses to neuronal signal transmission. However, ligands for many GPCRs remain unknown, suffer from off-target effects or have poor bioavailability. Additional challenges exist to dissect cell type-specific responses when the same GPCR is expressed on different cells within the body. Here, we overcome these limitations by engineering DREADD-based GPCR chimeras that selectively bind their agonist clozapine-N-oxide (CNO) and mimic a GPCR-of-interest. We show that the chimeric DREADD-β2-adrenergic receptor (β2AR/ADRB2) triggers comparable responses to levalbuterol on second messenger and kinase activity, post-translational modifications, and protein-protein interactions. Moreover, we successfully recapitulate β2AR-mediated filopodia formation in microglia, a β2AR-expressing immune cell that can drive inflammation in the nervous system. To further dissect microglial inflammation, we compared DREADD-β2AR with two additionally designed DREADD-based chimeras mimicking GPR65 and GPR109A/HCAR2, both enriched in microglia. DREADD-β2AR and DREADD-GPR65 modulate the inflammatory response with a similar profile as endogenously expressed β2AR, while DREADD-GPR109A had no impact. Our DREADD-based approach allows investigation of cell type-dependent signaling pathways and function without known endogenous ligands.

scholarly journals Targeted disruption of PKC from AKAP Signaling Complexes

2021 ◽  
Author(s):  
Ameya J. Limaye ◽  
George N. Bendzunas ◽  
Eileen Kennedy
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Signaling Pathways ◽  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Targeted Disruption ◽  
Physiological Processes ◽  
Kinase C ◽  
P Protein

Protein Kinase C (PKC) is a member of the AGC subfamily of kinases and regulates a wide array of signaling pathways and physiological processes. Protein-protein interactions involving PKC and its...

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 Expanding the potential genes of inborn errors of immunity through protein interactions

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Humza A. Khan ◽  
Manish J. Butte
Keyword(s):  
Genetic Variation ◽  
Protein Interactions ◽  
Immune Cell ◽  
Genetic Disorders ◽  
Cell Types ◽  
Protein Protein Interactions ◽  
Inborn Errors ◽  
Post Translational Modifications ◽  
New Genes ◽  
Inborn Errors Of Immunity

Abstract Background Inborn errors of immunity (IEI) are a group of genetic disorders that impair the immune system, with over 400 genes described so far, and hundreds more to be discovered. To facilitate the search for new genes, we need a way to prioritize among all the genes in the genome those most likely to play an important role in immunity. Results Here we identify a new list of genes by linking known IEI genes to new ones by using open-source databases of protein-protein interactions, post-translational modifications, and transcriptional regulation. We analyze this new set of 2,530 IEI-related genes for their tolerance of genetic variation and by their expression levels in various immune cell types. Conclusions By merging genes derived from protein interactions of known IEI genes with transcriptional data, we offer a new list of candidate genes that may play a role in as-yet undiscovered IEIs.

scholarly journals The adaptor protein Ste50 directly modulates yeast MAPK signaling specificity through differential connections of its RA domain

2019 ◽  
Vol 30 (6) ◽  
pp. 794-807
Author(s):  
Nusrat Sharmeen ◽  
Traian Sulea ◽  
Malcolm Whiteway ◽  
Cunle Wu
Keyword(s):  
Signaling Pathways ◽  
Protein Interactions ◽  
Mapk Pathway ◽  
Adaptor Protein ◽  
Filamentous Growth ◽  
Mapk Signaling ◽  
Yeast Cells ◽  
Signaling Specificity ◽  
Signaling Complex ◽  
And Function

Discriminating among diverse environmental stimuli is critical for organisms to ensure their proper development, homeostasis, and survival. Saccharomyces cerevisiae regulates mating, osmoregulation, and filamentous growth using three different MAPK signaling pathways that share common components and therefore must ensure specificity. The adaptor protein Ste50 activates Ste11p, the MAP3K of all three modules. Its Ras association (RA) domain acts in both hyperosmolar and filamentous growth pathways, but its connection to the mating pathway is unknown. Genetically probing the domain, we found mutants that specifically disrupted mating or HOG-signaling pathways or both. Structurally these residues clustered on the RA domain, forming distinct surfaces with a propensity for protein–protein interactions. GFP fusions of wild-type (WT) and mutant Ste50p show that WT is localized to the shmoo structure and accumulates at the growing shmoo tip. The specifically pheromone response–defective mutants are severely impaired in shmoo formation and fail to localize ste50p, suggesting a failure of association and function of Ste50 mutants in the pheromone-signaling complex. Our results suggest that yeast cells can use differential protein interactions with the Ste50p RA domain to provide specificity of signaling during MAPK pathway activation.

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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