Contribution of coupling between human myometrial β2-adrenoreceptor and the BKCa channel to uterine quiescence

The β2-adrenergic receptor (β2-AR) and the large-conductance Ca2+-activated K+ (BKCa) channel have been shown, separately, to be involved in mediating uterine relaxation. Our recent studies reveal that the levels of both β2-AR and BKCa channel proteins in pregnant human myometrium decrease by ∼50% after the onset of labor. We present direct evidence in support of a structural and functional association between the β2-AR and the BKCa channel in pregnant human myometrium. Localization of both proteins is predominantly plasmalemmal, with 60% of β2-AR colocalizing with the BKCa channel. Coimmunoprecipitation studies indicate that BKCa and β2-AR are structurally linked by direct protein-protein interactions. Functional correlation was confirmed by experiments of human myometrial contractility in which the BKCa channel blocker, paxilline, significantly antagonized the relaxant effect of the β2-AR agonist ritodrine. These novel findings provide an insight into the coupling between the β2-AR and BKCa channel and may have utility in the application of this signaling cascade for therapeutic potential in the management of preterm labor.

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A new insight into protein-protein interactions and the effect of conformational alterations in PCNA

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2020.01.212 ◽

2020 ◽

Vol 148 ◽

pp. 999-1009 ◽

Cited By ~ 15

Author(s):

Vijay Kumar Bhardwaj ◽

Rituraj Purohit

Keyword(s):

Protein Interactions ◽

Protein Protein Interactions ◽

Insight Into

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Getting into position: the catalytic mechanisms of protein ubiquitylation

Biochemical Journal ◽

10.1042/bj20040198 ◽

2004 ◽

Vol 379 (3) ◽

pp. 513-525 ◽

Cited By ~ 172

Author(s):

Lori A. PASSMORE ◽

David BARFORD

Keyword(s):

Protein Interactions ◽

Regulatory Elements ◽

Substrate Selection ◽

Protein Protein Interactions ◽

Different Types ◽

Catalytic Mechanisms ◽

Cellular Pathways ◽

Ubiquitin Conjugating Enzymes ◽

Insight Into

The role of protein ubiquitylation in the control of diverse cellular pathways has recently gained widespread attention. Ubiquitylation not only directs the targeted destruction of tagged proteins by the 26 S proteasome, but it also modulates protein activities, protein–protein interactions and subcellular localization. An understanding of the components involved in protein ubiquitylation (E1s, E2s and E3s) is essential to understand how specificity and regulation are conferred upon these pathways. Much of what we know about the catalytic mechanisms of protein ubiquitylation comes from structural studies of the proteins involved in this process. Indeed, structures of ubiquitin-activating enzymes (E1s) and ubiquitin-conjugating enzymes (E2s) have provided insight into their mechanistic details. E3s (ubiquitin ligases) contain most of the substrate specificity and regulatory elements required for protein ubiquitylation. Although several E3 structures are available, the specific mechanistic role of E3s is still unclear. This review will discuss the different types of ubiquitin signals and how they are generated. Recent advances in the field of protein ubiquitylation will be examined, including the mechanisms of E1, E2 and E3. In particular, we discuss the complexity of molecular recognition required to impose selectivity on substrate selection and topology of poly-ubiquitin chains.

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MiRNA-Regulated Pathways for Hypertrophic Cardiomyopathy: Network-Based Approach to Insight into Pathogenesis

Genes ◽

10.3390/genes12122016 ◽

2021 ◽

Vol 12 (12) ◽

pp. 2016

Author(s):

German Osmak ◽

Natalia Baulina ◽

Ivan Kiselev ◽

Olga Favorova

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Signaling Pathways ◽

Protein Interactions ◽

Target Gene ◽

High Throughput Sequencing ◽

Point Of View ◽

Specific Gene ◽

Protein Protein Interactions ◽

Insight Into ◽

Sarcomeric Genes

Hypertrophic cardiomyopathy (HCM) is the most common hereditary heart disease. The wide spread of high-throughput sequencing casts doubt on its monogenic nature, suggesting the presence of mechanisms of HCM development independent from mutations in sarcomeric genes. From this point of view, HCM may arise from the interactions of several HCM-associated genes, and from disturbance of regulation of their expression. We developed a bioinformatic workflow to study the involvement of signaling pathways in HCM development through analyzing data on human heart-specific gene expression, miRNA-target gene interactions, and protein–protein interactions, available in open databases. Genes regulated by a pool of miRNAs contributing to human cardiac hypertrophy, namely hsa-miR-1-3p, hsa-miR-19b-3p, hsa-miR-21-5p, hsa-miR-29a-3p, hsa-miR-93-5p, hsa-miR-133a-3p, hsa-miR-155-5p, hsa-miR-199a-3p, hsa-miR-221-3p, hsa-miR-222-3p, hsa-miR-451a, and hsa-miR-497-5p, were considered. As a result, we pinpointed a module of TGFβ-mediated SMAD signaling pathways, enriched by targets of the selected miRNAs, that may contribute to the cardiac remodeling in HCM. We suggest that the developed network-based approach could be useful in providing a more accurate glimpse on pathological processes in the disease pathogenesis.

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Regulation of cadherin dimerization by chemical fragments as a trigger to inhibit cell adhesion

Communications Biology ◽

10.1038/s42003-021-02575-3 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Akinobu Senoo ◽

Sho Ito ◽

Satoru Nagatoishi ◽

Yutaro Saito ◽

Go Ueno ◽

...

Keyword(s):

Cell Adhesion ◽

Hydrogen Bonds ◽

Small Molecules ◽

Small Molecule ◽

Protein Interactions ◽

Therapeutic Potential ◽

Protein Complexes ◽

Protein Protein Interactions ◽

Specific Chemical ◽

Stepwise Assembly

AbstractMany cadherin family proteins are associated with diseases such as cancer. Since cell adhesion requires homodimerization of cadherin molecules, a small-molecule regulator of dimerization would have therapeutic potential. Herein, we describe identification of a P-cadherin-specific chemical fragment that inhibits P-cadherin-mediated cell adhesion. Although the identified molecule is a fragment compound, it binds to a cavity of P-cadherin that has not previously been targeted, indirectly prevents formation of hydrogen bonds necessary for formation of an intermediate called the X dimer and thus modulates the process of X dimerization. Our findings will impact on a strategy for regulation of protein-protein interactions and stepwise assembly of protein complexes using small molecules.

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Self-diffusion of a highly concentrated monoclonal antibody by fluorescence correlation spectroscopy: insight into protein–protein interactions and self-association

Soft Matter ◽

10.1039/c9sm01071h ◽

2019 ◽

Vol 15 (33) ◽

pp. 6660-6676 ◽

Cited By ~ 2

Author(s):

Jessica J. Hung ◽

Wade F. Zeno ◽

Amjad A. Chowdhury ◽

Barton J. Dear ◽

Kishan Ramachandran ◽

...

Keyword(s):

Monoclonal Antibody ◽

Protein Interactions ◽

Fluorescence Correlation Spectroscopy ◽

Correlation Spectroscopy ◽

Protein Protein Interactions ◽

Fluorescence Correlation ◽

Self Diffusion ◽

Self Association ◽

Insight Into

Measurement and interpretation of self-diffusion of a highly concentrated mAb with different formulations in context of viscosity and protein self-interactions.

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Occurrence of the d-Proline Chemotype in Enzyme Inhibitors

Symmetry ◽

10.3390/sym11040558 ◽

2019 ◽

Vol 11 (4) ◽

pp. 558 ◽

Cited By ~ 2

Author(s):

Elena Lenci ◽

Andrea Trabocchi

Keyword(s):

Amino Acids ◽

Protein Interactions ◽

Medicinal Chemistry ◽

Enzyme Inhibitors ◽

Proteolytic Enzymes ◽

Building Blocks ◽

Protein Protein Interactions ◽

Conformationally Constrained ◽

Biological Outcomes ◽

Insight Into

Natural and nonnatural amino acids represent important building blocks for the development of peptidomimetic scaffolds, especially for targeting proteolytic enzymes and for addressing protein–protein interactions. Among all the different amino acids derivatives, proline is particularly relevant in chemical biology and medicinal chemistry due to its secondary structure’s inducing and stabilizing properties. Also, the pyrrolidine ring is a conformationally constrained template that can direct appendages into specific clefts of the enzyme binding site. Thus, many papers have appeared in the literature focusing on the use of proline and its derivatives as scaffolds for medicinal chemistry applications. In this review paper, an insight into the different biological outcomes of d-proline and l-proline in enzyme inhibitors is presented, especially when associated with matrix metalloprotease and metallo-β-lactamase enzymes.

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Specific Inhibition of HIF Activity: Can Peptides Lead the Way?

Cancers ◽

10.3390/cancers13030410 ◽

2021 ◽

Vol 13 (3) ◽

pp. 410

Author(s):

Ilias Mylonis ◽

Georgia Chachami ◽

George Simos

Keyword(s):

Transcription Factors ◽

Small Molecules ◽

Protein Interactions ◽

Cellular Response ◽

Therapeutic Potential ◽

Special Focus ◽

Hypoxia Inducible Factors ◽

Protein Protein Interactions ◽

Pharmacological Agents ◽

Specific Manner

Reduced oxygen availability (hypoxia) is a characteristic of many disorders including cancer. Central components of the systemic and cellular response to hypoxia are the Hypoxia Inducible Factors (HIFs), a small family of heterodimeric transcription factors that directly or indirectly regulate the expression of hundreds of genes, the products of which mediate adaptive changes in processes that include metabolism, erythropoiesis, and angiogenesis. The overexpression of HIFs has been linked to the pathogenesis and progression of cancer. Moreover, evidence from cellular and animal models have convincingly shown that targeting HIFs represents a valid approach to treat hypoxia-related disorders. However, targeting transcription factors with small molecules is a very demanding task and development of HIF inhibitors with specificity and therapeutic potential has largely remained an unattainable challenge. Another promising approach to inhibit HIFs is to use peptides modelled after HIF subunit domains known to be involved in protein–protein interactions that are critical for HIF function. Introduction of these peptides into cells can inhibit, through competition, the activity of endogenous HIFs in a sequence and, therefore also isoform, specific manner. This review summarizes the involvement of HIFs in cancer and the approaches for targeting them, with a special focus on the development of peptide HIF inhibitors and their prospects as highly-specific pharmacological agents.

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Structure of the Q237W mutant of HhaI DNA methyltransferase: an insight into protein-protein interactions

Biological Chemistry ◽

10.1515/bchm.385.13.373.57208 ◽

2004 ◽

Vol 385 (13) ◽

pp. 373-379 ◽

Cited By ~ 7

Author(s):

A. Dong ◽

L. Zhou ◽

X. Zhang ◽

S. Stickel ◽

R.J. Roberts ◽

...

Keyword(s):

Protein Interactions ◽

Dna Methyltransferase ◽

Protein Protein Interactions ◽

Insight Into

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A Bufadienolide-Enriched Fraction of Bryophyllum pinnatum Inhibits Human Myometrial Contractility In Vitro

Planta Medica ◽

10.1055/a-0810-7704 ◽

2018 ◽

Vol 85 (05) ◽

pp. 385-393 ◽

Cited By ~ 2

Author(s):

Stefanie Santos ◽

Christian Haslinger ◽

Kristian Klaic ◽

Maria Faleschini ◽

Mónica Mennet ◽

...

Keyword(s):

Cell Viability ◽

Area Under The Curve ◽

Progressive Increase ◽

Human Myometrium ◽

Organ Bath ◽

Relaxant Effect ◽

System Cell ◽

Myometrial Contractility ◽

Bryophyllum Pinnatum

Abstract Bryophyllum pinnatum has been used since the 1970s to prevent premature labour, first in anthroposophic hospitals and, more recently, also in the main Swiss perinatal centres. However, it is not known which compounds in B. pinnatum leaves contribute to the tocolytic effect. Here we studied the effects of a flavonoid-enriched fraction, the corresponding flavonoid aglycon mixture, a bufadienolide-enriched fraction, and B. pinnatum leaf press juice on human myometrial contractility in vitro. The strength (area under the curve and amplitude) and frequency of contractions were recorded using strips of human myometrium mounted in an organ bath system. Cell viability assays were performed with the human myometrium hTERT-C3 and PHM1 – 41 cell lines. Repeated addition of the flavonoid-enriched fraction, flavonoid aglycon mixture, bufadienolide-enriched fraction, or B. pinnatum leaf press juice led to a progressive decrease of contraction strength, without jeopardising the vitality of myometrium strips. The bufadienolide-enriched fraction was the most active, since 1 µg/mL of the bufadienolide-enriched fraction lowered the area under the curve to 40.1 ± 11.8% of the initial value, whereas 150 µg/mL of the flavonoid-enriched fraction, 6.2 µg/mL of the flavonoid aglycon mixture, and 10 µg/mL of the B. pinnatum leaf press juice were required to achieve comparable inhibition. A progressive increase of contraction frequency was observed, except in the case of the flavonoid aglycon mixture, which did not affect frequency. None of the test substances decreased myometrial cell viability, even at concentrations of 500 µg/mL of the flavonoid-enriched fraction, 40 µg/mL of the flavonoid aglycon mixture, 3.8 µg/mL of the bufadienolide-enriched fraction, and 75 µg/mL of the B. pinnatum leaf press juice, i.e., higher than those used in the myometrium experiments. Given the concentrations of flavonoids in the flavonoid-enriched fraction and B. pinnatum leaf press juice, and of bufadienolides in the bufadienolide-enriched fraction and B. pinnatum leaf press juice, it appears that bufadienolides may be mainly responsible for the relaxant effect.

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