Snake Venom Disintegrins: An Overview of their Interaction with Integrins

2019 ◽  
Vol 20 (4) ◽  
pp. 465-477 ◽  
Author(s):  
Pedro Henrique Souza Cesar ◽  
Mariana Aparecida Braga ◽  
Marcus Vinicius Cardoso Trento ◽  
Danilo Luccas Menaldo ◽  
Silvana Marcussi
Keyword(s):  
Signal Transduction ◽  
Cell Surface ◽  
Essential Role ◽  
Antitumor Agents ◽  
Structural Models ◽  
New Drugs ◽  
Snake Venoms ◽  
Cellular Processes ◽  
Pharmacological Potential ◽  
Direct Use

Disintegrins are non-enzymatic proteins that interfere on cell–cell interactions and signal transduction, contributing to the toxicity of snake venoms and play an essential role in envenomations. Most of their pharmacological and toxic effects are the result of the interaction of these molecules with cell surface ligands, which has been widely described and studied. These proteins may act on platelets, leading to hemorrhage, and may also induce apoptosis and cytotoxicity, which highlights a high pharmacological potential for the development of thrombolytic and antitumor agents. Additionally, these molecules interfere with the functions of integrins by altering various cellular processes such as migration, adhesion and proliferation. This review gathers information on functional characteristics of disintegrins isolated from snake venoms, emphasizing a comprehensive view of the possibility of direct use of these molecules in the development of new drugs, or even indirectly as structural models.

scholarly journals The Membrane Associated RING-CH Proteins: A Family of E3 Ligases with Diverse Roles through the Cell

2014 ◽  
Vol 2014 ◽  
pp. 1-23 ◽  
Author(s):  
Tasleem Samji ◽  
Soonwook Hong ◽  
Robert E. Means
Keyword(s):  
Signal Transduction ◽  
Dna Repair ◽  
Essential Role ◽  
Proteolytic Degradation ◽  
Diverse Range ◽  
E3 Ligases ◽  
Cellular Processes ◽  
Range Of Functions ◽  
Membrane Bound ◽  
Lines Of Evidence

Since the discovery that conjugation of ubiquitin to proteins can drive proteolytic degradation, ubiquitination has been shown to perform a diverse range of functions in the cell. It plays an important role in endocytosis, signal transduction, trafficking of vesicles inside the cell, and even DNA repair. The process of ubiquitination-mediated control has turned out to be remarkably complex, involving a diverse array of proteins and many levels of control. This review focuses on a family of structurally related E3 ligases termed the membrane-associated RING-CH (MARCH) ubiquitin ligases, which were originally discovered as structural homologs to the virals E3s, K3, and K5 from Kaposi’s sarcoma-associated herpesvirus (KSHV). These proteins contain a catalytic RING-CH finger and are typically membrane-bound, with some having up to 14 putative transmembrane domains. Despite several lines of evidence showing that the MARCH proteins play a complex and essential role in several cellular processes, this family remains understudied.

Pharmacological Targeting of Neuronal Kv7.2/3 Channels: A Focus on Chemotypes and Receptor Sites

2018 ◽  
Vol 25 (23) ◽  
pp. 2637-2660 ◽  
Author(s):  
Francesco Miceli ◽  
Maria V. Soldovieri ◽  
Paolo Ambrosino ◽  
Laura Manocchio ◽  
Ilaria Mosca ◽  
...  
Keyword(s):  
Metabolic Diseases ◽  
Scientific Literature ◽  
New Drugs ◽  
Current Status ◽  
Functional Heterogeneity ◽  
Molecular Scaffolds ◽  
Kv7 Channels ◽  
Receptor Sites ◽  
Pharmacological Targets ◽  
Pharmacological Potential

Background: The Kv7 (KCNQ) subfamily of voltage-gated potassium channels consists of 5 members (Kv7.1-5) each showing characteristic tissue distribution and physiological roles. Given their functional heterogeneity, Kv7 channels represent important pharmacological targets for the development of new drugs for neuronal, cardiovascular and metabolic diseases. <p> Objective: In the present manuscript, we focus on describing the pharmacological relevance and potential therapeutic applications of drugs acting on neuronally-expressed Kv7.2/3 channels, placing particular emphasis on the different chemotypes, and highlighting their pharmacodynamic and, whenever possible, pharmacokinetic peculiarities. <p> Methods: The present work is based on an in-depth search of the currently available scientific literature, and on our own experience and knowledge in the field of neuronal Kv7 channel pharmacology. Space limitations impeded to describe the full pharmacological potential of Kv7 channels; thus, we have chosen to focus on neuronal channels composed of Kv7.2 and Kv7.3 subunits, and to mainly concentrate on their involvement in epilepsy. <p> Results: An astonishing heterogeneity in the molecular scaffolds exploitable to develop Kv7.2/3 modulators is evident, with important structural/functional peculiarities of distinct compound classes. <p> Conclusion: In the present work we have attempted to show the current status and growing potential of the Kv7 pharmacology field. We anticipate a bright future for the field, and express our hopes that the efforts herein reviewed will result in an improved treatment of hyperexcitability (or any other) diseases.

scholarly journals Interaction of Pestiviral E1 and E2 Sequences in Dimer Formation and Intracellular Retention

2021 ◽  
Vol 22 (14) ◽  
pp. 7285
Author(s):  
Yu Mu ◽  
Birke Andrea Tews ◽  
Christine Luttermann ◽  
Gregor Meyers
Keyword(s):  
Life Cycle ◽  
Cell Surface ◽  
Double Mutant ◽  
Essential Role ◽  
Infectious Clone ◽  
Intracellular Localization ◽  
Dimer Formation ◽  
Covalent Linkage ◽  
Crucial Step ◽  
Retention Signal

Pestiviruses contain three envelope proteins: Erns, E1, and E2. Expression of HA-tagged E1 or mutants thereof showed that E1 forms homodimers and -trimers. C123 and, to a lesser extent, C171, affected the oligomerization of E1 with a double mutant C123S/C171S preventing oligomerization completely. E1 also establishes disulfide linked heterodimers with E2, which are crucial for the recovery of infectious viruses. Co-expression analyses with the HA-tagged E1 wt/E1 mutants and E2 wt/E2 mutants demonstrated that C123 in E1 and C295 in E2 are the critical sites for E1/E2 heterodimer formation. Introduction of mutations preventing E1/E2 heterodimer formation into the full-length infectious clone of BVDV CP7 prevented the recovery of infectious viruses, proving that C123 in E1 and C295 in E2 play an essential role in the BVDV life cycle, and further support the conclusion that heterodimer formation is the crucial step. Interestingly, we found that the retention signal of E1 is mandatory for intracellular localization of the heterodimer, so that absence of the E1 retention signal directs the heterodimer to the cell surface even though the E2 retention signal is still present. The covalent linkage between E1 and E2 plays an essential role for this process.

scholarly journals Pharmacological Characterisation of Pseudocerastes and Eristicophis Viper Venoms Reveal Anticancer (Melanoma) Properties and a Potentially Novel Mode of Fibrinogenolysis

2021 ◽  
Vol 22 (13) ◽  
pp. 6896
Author(s):  
Bianca op den Brouw ◽  
Parviz Ghezellou ◽  
Nicholas R. Casewell ◽  
Syed Abid Ali ◽  
Behzad Fathinia ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Serine Proteases ◽  
Human Melanoma ◽  
Snake Venoms ◽  
Lead Compounds ◽  
Bioactive Properties ◽  
Fibrinogenolytic Activity ◽  
Pharmacological Potential ◽  
Hydrolysis Of ◽  
Viper Venoms

Venoms are a rich source of potential lead compounds for drug discovery, and descriptive studies of venom form the first phase of the biodiscovery process. In this study, we investigated the pharmacological potential of crude Pseudocerastes and Eristicophis snake venoms in haematological disorders and cancer treatment. We assessed their antithrombotic potential using fibrinogen thromboelastography, fibrinogen gels with and without protease inhibitors, and colourimetric fibrinolysis assays. These assays indicated that the anticoagulant properties of the venoms are likely induced by the hydrolysis of phospholipids and by selective fibrinogenolysis. Furthermore, while most fibrinogenolysis occurred by the direct activity of snake venom metalloproteases and serine proteases, modest evidence indicated that fibrinogenolytic activity may also be mediated by selective venom phospholipases and an inhibitory venom-derived serine protease. We also found that the Pseudocerastes venoms significantly reduced the viability of human melanoma (MM96L) cells by more than 80%, while it had almost no effect on the healthy neonatal foreskin fibroblasts (NFF) as determined by viability assays. The bioactive properties of these venoms suggest that they contain a number of toxins suitable for downstream pharmacological development as candidates for antithrombotic or anticancer agents.

scholarly journals Hanks-Type Serine/Threonine Protein Kinases and Phosphatases in Bacteria: Roles in Signaling and Adaptation to Various Environments

2018 ◽  
Vol 19 (10) ◽  
pp. 2872 ◽  
Author(s):  
Monika Janczarek ◽  
José-María Vinardell ◽  
Paulina Lipa ◽  
Magdalena Karaś
Keyword(s):  
Dna Binding ◽  
Essential Role ◽  
Current Knowledge ◽  
Response Regulator ◽  
Protein Targets ◽  
Regulatory Pathways ◽  
Translational Machinery ◽  
Signaling Systems ◽  
Cellular Processes ◽  
Division Cell

Reversible phosphorylation is a key mechanism that regulates many cellular processes in prokaryotes and eukaryotes. In prokaryotes, signal transduction includes two-component signaling systems, which involve a membrane sensor histidine kinase and a cognate DNA-binding response regulator. Several recent studies indicate that alternative regulatory pathways controlled by Hanks-type serine/threonine kinases (STKs) and serine/threonine phosphatases (STPs) also play an essential role in regulation of many different processes in bacteria, such as growth and cell division, cell wall biosynthesis, sporulation, biofilm formation, stress response, metabolic and developmental processes, as well as interactions (either pathogenic or symbiotic) with higher host organisms. Since these enzymes are not DNA-binding proteins, they exert the regulatory role via post-translational modifications of their protein targets. In this review, we summarize the current knowledge of STKs and STPs, and discuss how these enzymes mediate gene expression in prokaryotes. Many studies indicate that regulatory systems based on Hanks-type STKs and STPs play an essential role in the regulation of various cellular processes, by reversibly phosphorylating many protein targets, among them several regulatory proteins of other signaling cascades. These data show high complexity of bacterial regulatory network, in which the crosstalk between STK/STP signaling enzymes, components of TCSs, and the translational machinery occurs. In this regulation, the STK/STP systems have been proved to play important roles.

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