Molecular Insights Into the Interaction of HPV-16 E6 Variants Against MAGI-1 PDZ1 Domain

Oncogenic protein E6 from Human Papilloma Virus 16 (HPV-16) mediates the degradation of Membrane-associated guanylate kinase with inverted domain structure-1 (MAGI-1), throughout the interaction of its protein binding motif (PBM) with the Discs-large homologous regions 1 (PDZ1) domain of MAG1-1. Generic variation in the E6 gene that translates to changes in the protein’s amino acidic sequence modifies the interaction of E6 with the cellular protein MAGI-1. MAGI-1 is a scaffolding protein found at tight junctions of epithelial cells, where it interacts with a variety of proteins regulating signaling pathways. MAGI-1 is a multidomain protein containing two WW (rsp-domain-9), one guanylate kinase-like, and six PDZ domains. PDZ domains played an important role in the function of MAGI-1 and served as targets for several viral proteins including the HPV-16 E6. The aim of this work was to evaluate, with an in silico approach, employing molecular dynamics simulation and protein-protein docking, the interaction of the intragenic variants E-G350 (L83V), E-C188/G350 (E29Q/L83V), E-A176/G350 (D25N/L83V), E6-AAa (Q14H/H78Y/83V) y E6-AAc (Q14H/I27RH78Y/L83V) and E6-reference of HPV-16 with MAGI-1. We found that variants E-G350, E-C188/G350, E-A176/G350, AAa and AAc increase their affinity to our two models of MAGI-1 compared to E6-reference.

Insights in the Interaction of HPV-16 E6 and Its Variants (E-G350, E-A176/G350, E-C188/G350, AAa and AAc) with MAGI-1

Oncogenic protein E6 from Human Papilloma Virus 16 (HPV-16) mediates the degradation of Membrane-associated guanylate kinase with inverted domain structure-1 (MAGI-1), throughout the interaction of its protein binding motif (PBM) with the Discs-large homologous regions 1 (PDZ1) domain of MAG1-1. Generic variation in the E6 gene that translates to changes in the protein’s amino acidic sequence modifies the interaction of E6 with the cellular protein MAGI-1. MAGI-1 is a scaffolding protein found at tight junctions of epithelial cells, where it interacts with a variety of proteins regulating signaling pathways. MAGI-1 is a multidomain protein containing two WW (rsp-domain-9), one guanylate kinase-like, and six PDZ domains. PDZ domains played an important role in the function of MAGI-1 and served as targets for several viral proteins including the HPV-16 E6. The aim of this work was to evaluate, with an in silico approach, employing molecular dynamics simulation and protein-protein docking, the interaction of the intragenic variants E-G350 (L83V), E-C188/G350 (E29Q/L83V), E-A176/G350 (D25N/L83V), E6-AAa (Q14H/H78Y/83V) y E6-AAc (Q14H/I27RH78Y/L83V) and E6-reference of HPV-16 with MAGI-1. We found that variants E-G350, E-C188/G350, E-A176/G350, AAa and AAc increase their affinity to our two models of MAGI-1 compared to E6-reference.

Role of ADP Ribosylation Factor Guanylate Kinase 1 in the Malignant Biological Behavior of Gastric Cancer

Objectives: To study the effects of ADP ribosylation factor guanylate kinase 1 gene (ASAP1) on the biological behavior of malignant gastric cancer (GC), and explore its possible molecular mechanisms in tumorigenesis and tumor progression.Methods: Quantitative PCR and western blotting (WB) were performed to measure ASAP1 mRNA and protein expression in the GES-1 epithelial cell line, which is derived from normal human mucosa, and three GC cell lines. Molecular biology techniques such as lentivirus packaging, infection, and screening were used to obtain BGC823 GC cells overexpressing ASAP1 and BGC823 and MKN45 cells with ASAP1 knocked down. The Cell Counting Kit-8 assay, colony formation assay, flow cytometry using Annexin V/propidium iodide, Transwell migration and invasion assays, and scratch assay were used to assess the malignant biological behavior of GC cells with ASAP1 overexpression and knockdown. WB was conducted to evaluate the effects of ASAP1 expression on angiogenesis, as well as on the expression of matrix metalloproteinases (MMPs), apoptotic proteins, and epithelial-mesenchymal transition (EMT)-related proteins. Nude mice bearing transplanted tumors were evaluated to determine the effect of ASAP1 knockdown on BGC823 GC cells.Results: ASAP1 expression in GC cells was greater than that in GES-1 normal gastric mucosal epithelial cells. ASAP1 overexpression significantly enhanced the proliferation, invasion, and migration of GC cells and reduced apoptosis; whereas ASAP1 knockdown significantly reduced the proliferation, invasion, and migration of GC cells and promoted apoptosis. In the ASAP1-knockdown group, expression of cleaved-caspase 3, cleaved-poly-ADP-ribose polymerase (PARP), and the epithelial marker E-cadherin increased significantly, whereas the expression of MMP2, MMP9, vascular endothelial growth factor A (VEGFA), and the mesenchymal markers N-cadherin, and vimentin decreased significantly (P<0.01). Knockdown of ASAP1 inhibited the growth of subcutaneously implanted tumors in nude mice.Conclusions: ASAP1 overexpression strongly promotes—whereas knockdown of ASAP1 effectively weakens—the malignant biological behavior of GC cells, possibly by reducing VEGFA expression and thus reducing angiogenesis, upregulating the expression of cleaved-caspase 3 and cleaved-PARP, and reducing the activity of MMPs and EMT.

Genome-Scale Metabolic Model of Infection with SARS-CoV-2 Mutants Confirms Guanylate Kinase as Robust Potential Antiviral Target

The current SARS-CoV-2 pandemic is still threatening humankind. Despite first successes in vaccine development and approval, no antiviral treatment is available for COVID-19 patients. The success is further tarnished by the emergence and spreading of mutation variants of SARS-CoV-2, for which some vaccines have lower efficacy. This highlights the urgent need for antiviral therapies even more. This article describes how the genome-scale metabolic model (GEM) of the host-virus interaction of human alveolar macrophages and SARS-CoV-2 was refined by incorporating the latest information about the virus’s structural proteins and the mutant variants B.1.1.7, B.1.351, B.1.28, B.1.427/B.1.429, and B.1.617. We confirmed the initially identified guanylate kinase as a potential antiviral target with this refined model and identified further potential targets from the purine and pyrimidine metabolism. The model was further extended by incorporating the virus’ lipid requirements. This opened new perspectives for potential antiviral targets in the altered lipid metabolism. Especially the phosphatidylcholine biosynthesis seems to play a pivotal role in viral replication. The guanylate kinase is even a robust target in all investigated mutation variants currently spreading worldwide. These new insights can guide laboratory experiments for the validation of identified potential antiviral targets. Only the combination of vaccines and antiviral therapies will effectively defeat this ongoing pandemic.

Interaction between the guanylate kinase domain of PSD-95 and the proline-rich region and microtubule binding repeats 2 and 3 of tau

The microtubule-associated protein tau is a key factor in neurodegenerative proteinopathies and is predominantly found in the neuronal axon. However, somatodendritic localization of tau occurs for a subset of pathological and physiologic tau. Dendritic tau can localize to post-synapses where it interacts with proteins of the post-synaptic density (PSD) protein PSD-95, a membrane-associated guanylate kinase (MAGUK) scaffold factor for organization of protein complexes within the PSD, to mediate downstream signals. The sub-molecular details of this interaction, however, remain unclear. Here, we use interaction mapping in cultured cells to demonstrate that tau interacts with the guanylate kinase (GUK) domain in the C-terminal region of PSD-95. The PSD-95 GUK domain is required and sufficient for a complex with full-length human tau. Mapping the interaction of the MAGUK core on tau revealed the microtubule binding repeats 2 and 3 and the proline-rich region contribute to this interaction, while the N- and C-terminal regions of tau inhibit interaction. These results reveal intramolecular determinants of the protein complex of tau and PSD-95 and increase our understanding of tau interactions regulating neurotoxic signaling at the molecular level.

Repurposing Amantadine and Memantine for COVID-19: Guanylate Kinases Might Pave the Road towards Novel SARS CoV-2 and Anti Neoplastic Therapeutics.

Guanylate kinase 1 (GK1) was suggested to play a crucial role in SARS CoV-2 replication and previous studies have suggested a role in the pathogenesis of some neoplasms. We are providing a concise strengths, weaknesses, opportunities, and threats (SWOT) analysis of this hypothesis while discussing guanylate kinase physiological function, pharmacological importance. Importantly, though GK1 role in SARS CoV-2 replication might prove valid, the available experimental inhibitors of GK 1 might not, at least for the short term, be safely used to manage COVID-19. However, we suggest assessing another potential interaction between SARS CoV-2 and the non-authentic membrane-associated guanylate kinases as we suggest this might add to consider the potential role of the NMDA antagonists amantadine and memantine in COVID-19 management for and we have recommended clinical trials for selected described COVID-19 patients. Finally, we also recommend conducting genetic, physiological, and immunological studies to explore the long-term potentials of novel GK-1 inhibitors suggesting they might eventually lead to a novel COVID-19 and cancer pharmacotherapeutics.

Role of Guanylate kinase 1 in SARS CoV-2 Replication and tumorigenesis: Potential Role for Amantadine and Novel Therapeutics in COVID-19 and Cancer Management.

A recent study has suggested that guanylate kinase 1 (GK1) plays a crucial role in SARS CoV-2 replication and recommended to test GK 1 inhibitors for invitro experiments and previous studies have suggested a role in the pathogenesis of some neoplasms. We are providing a concise strengths, weaknesses, opportunities, and threats (SWOT) analysis of this hypothesis while discussing guanylate kinase physiological function, pharmacological importance. Importantly, we suggest assessing another potential interaction between SARS CoV-2 and the non-authentic membrane-associated guanylate kinases as we suggest this might add to consider the potential role of amantadine in COVID-19 management. Moreover, though GK1 role in SARS CoV-2 replication might prove valid, the available experimental inhibitors of GK 1 might not, at least for the short term, be safely used to manage COVID-19. Finally, we recommend conducting genetic, physiological, and immunological studies to explore the long-term potentials of GK-1 inhibitors suggesting they might eventually lead to a novel COVID-19 and cancer pharmacotherapeutics.

SARS CoV-2 Replication and Neoplasm Pathogenesis Attributed to Guanylate kinase 1: Could it be A New Horizon for Pharmacotherapeutics?

A recent study has suggested that guanylate kinase 1 (GK1) plays a crucial role in SARS CoV-2 replication and recommended to test GK 1 inhibitors for invitro experiments and previous studies have suggested a role in the pathogenesis of some neoplasms. We are providing a concise strengths, weaknesses, opportunities, and threats (SWOT) analysis of this study while discussing guanylate kinase physiological function, pharmacological importance. Importantly, we suggest that though this hypothesis might prove valid, the available experimental GK 1 inhibitors might not, at least for the short term, be safely used to manage COVID-19. Moreover, we recommend conducting genetic, physiological, and immunological studies to explore the long-term potentials of GK-1 inhibitors suggesting they might eventually lead to a new horizon of both COVID-19 and cancer pharmacotherapeutics.

SARS CoV-2 Replication Attributed to Guanylate kinase 1: A SWOT Analysis

A recent interesting study has suggested that guanylate kinase 1 (GK1) plays a crucial role in SARS CoV-2 replication and recommended to test GK 1 inhibitors for invitro experiments. We are providing a concise strengths, weaknesses, opportunities, and threats (SWOT) analysis while discussing guanylate kinase physiological function, pharmacological importance. Importantly, we argue that though this hypothesis might prove valid, GK 1 inhibitors are very unlikely, at least for the short term, to be beneficial in clinical management of COVID-19. However, we recommend conducting focused genetic studies to test their suggested hypothesis as it might add to our knowledge of some COVID-19 encountered idiosyncratic morbidity and mortality outcomes.