Molecular Insight Into the Mutation Within Critical Zinc2+-Binding Site in the PAS Domain of WalK in Vancomycin-Intermediate Resistant Staphylococcus Aureus

Abstract Vancomycin-intermediate resistant Staphylococcus aureus (VISA), one of the common causes of nosocomial infection, is developed by mutations, including in walKR, with unclear molecular mechanisms. Although studies have verified some of these mutations, there are a few studies to pay attention to the importance of molecular modeling of mutations. Here, the Sanger sequencing for comparing gene sequences of WlKR between a VISA and its parental strain revealed mutation WalK-H364R. Structural protein mapping showed that H364R was located in a functional zinc ion coordinating residue within the cytoplasmic Per-Arnt-Sim (PAS) domain. The structural and functional effects of this mutation were analyzed using molecular computational approaches based on the recently determined crystal structures of the PAS domain of S. aureus. WalK-H364R was predicted to destabilize protein and decrease WalK interactions with proteins and nucleic acids. The qRT-PCR method showed downregulation of walKR and WalKR-regulated autolysins, which verified the molecular computational results.Overall, WalK-H364R within a critical metal-coordinating site is linked to VISA development through the walKR gene expression changes as well as the destructive effects on protein.Therefore, molecular modeling can be provided detailed insight into the molecular mechanism of VISA development, in particular, where complementation experiments are not readily available.

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Investigating the effect of an identified mutation within a critical site of PAS domain of WalK protein in a vancomycin-intermediate resistant Staphylococcus aureus by computational approaches

BMC Microbiology ◽

10.1186/s12866-021-02298-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Neda Baseri ◽

Shahin Najar-Peerayeh ◽

Bita Bakhshi

Keyword(s):

Staphylococcus Aureus ◽

Molecular Modelling ◽

Molecular Mechanisms ◽

Zinc Ion ◽

Pas Domain ◽

Structural Protein ◽

Computational Approaches ◽

Protein Mapping ◽

Critical Metal ◽

Related Proteins

Abstract Background Vancomycin-intermediate resistant Staphylococcus aureus (VISA) is becoming a common cause of nosocomial infections worldwide. VISA isolates are developed by unclear molecular mechanisms via mutations in several genes, including walKR. Although studies have verified some of these mutations, there are a few studies that pay attention to the importance of molecular modelling of mutations. Method For genomic and transcriptomic comparisons in a laboratory-derived VISA strain and its parental strain, Sanger sequencing and reverse transcriptase quantitative PCR (RT-qPCR) methods were used, respectively. After structural protein mapping of the detected mutation, mutation effects were analyzed using molecular computational approaches and crystal structures of related proteins. Results A mutation WalK-H364R was occurred in a functional zinc ion coordinating residue within the PAS domain in the VISA strain. WalK-H364R was predicted to destabilize protein and decrease WalK interactions with proteins and nucleic acids. The RT-qPCR method showed downregulation of walKR, WalKR-regulated autolysins, and agr locus. Conclusion Overall, WalK-H364R mutation within a critical metal-coordinating site was presumably related to the VISA development. We assume that the WalK-H364R mutation resulted in deleterious effects on protein, which was verified by walKR gene expression changes.. Therefore, molecular modelling provides detailed insight into the molecular mechanism of VISA development, in particular, where allelic replacement experiments are not readily available.

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Molecular Insight Into the Mutation Within Critical Zinc2+-Binding Site in the PAS Domain of WalK in Vancomycin-Intermediate Resistant Staphylococcus Aureus

10.21203/rs.3.rs-131302/v2 ◽

2021 ◽

Keyword(s):

Staphylococcus Aureus ◽

Binding Site ◽

Pas Domain ◽

Insight Into

Abstract The authors have requested that this preprint be withdrawn due to erroneous posting.

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Clinical Candidates Targeting the ATR–CHK1–WEE1 Axis in Cancer

Cancers ◽

10.3390/cancers13040795 ◽

2021 ◽

Vol 13 (4) ◽

pp. 795

Author(s):

Lukas Gorecki ◽

Martin Andrs ◽

Jan Korabecny

Keyword(s):

Cell Cycle ◽

Cancer Cells ◽

Molecular Mechanisms ◽

Patient Survival ◽

Current Status ◽

Future Perspectives ◽

Phase Ii Trials ◽

Anticancer Treatment ◽

Positive Outlook ◽

Insight Into

Selective killing of cancer cells while sparing healthy ones is the principle of the perfect cancer treatment and the primary aim of many oncologists, molecular biologists, and medicinal chemists. To achieve this goal, it is crucial to understand the molecular mechanisms that distinguish cancer cells from healthy ones. Accordingly, several clinical candidates that use particular mutations in cell-cycle progressions have been developed to kill cancer cells. As the majority of cancer cells have defects in G1 control, targeting the subsequent intra‑S or G2/M checkpoints has also been extensively pursued. This review focuses on clinical candidates that target the kinases involved in intra‑S and G2/M checkpoints, namely, ATR, CHK1, and WEE1 inhibitors. It provides insight into their current status and future perspectives for anticancer treatment. Overall, even though CHK1 inhibitors are still far from clinical establishment, promising accomplishments with ATR and WEE1 inhibitors in phase II trials present a positive outlook for patient survival.

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A Molecular Insight into the Synergistic Mechanism of Nigella sativa (Black Cumin) with β-Lactam Antibiotics against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Applied Sciences ◽

10.3390/app11073206 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3206

Author(s):

Lorina I. Badger-Emeka ◽

Promise Madu Emeka ◽

Hairul Islam M. Ibrahim

Keyword(s):

Staphylococcus Aureus ◽

Mechanism Of Action ◽

Methicillin Resistant Staphylococcus Aureus ◽

Nigella Sativa ◽

Synergistic Effects ◽

Diffusion Method ◽

Methicillin Resistant ◽

Cell Wall Disruption ◽

Time Kill ◽

Insight Into

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.

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Molecular Pathways Involved in the Development of Congenital Erythrocytosis

Genes ◽

10.3390/genes12081150 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1150

Author(s):

Jana Tomc ◽

Nataša Debeljak

Keyword(s):

Signal Transduction ◽

Iron Homeostasis ◽

Molecular Mechanisms ◽

Oxygen Affinity ◽

Molecular Pathways ◽

Disease Development ◽

Post Translational Modifications ◽

Hemoglobin Oxygen Affinity ◽

Insight Into ◽

Idiopathic Erythrocytosis

Patients with idiopathic erythrocytosis are directed to targeted genetic testing including nine genes involved in oxygen sensing pathway in kidneys, erythropoietin signal transduction in pre-erythrocytes and hemoglobin-oxygen affinity regulation in mature erythrocytes. However, in more than 60% of cases the genetic cause remains undiagnosed, suggesting that other genes and mechanisms must be involved in the disease development. This review aims to explore additional molecular mechanisms in recognized erythrocytosis pathways and propose new pathways associated with this rare hematological disorder. For this purpose, a comprehensive review of the literature was performed and different in silico tools were used. We identified genes involved in several mechanisms and molecular pathways, including mRNA transcriptional regulation, post-translational modifications, membrane transport, regulation of signal transduction, glucose metabolism and iron homeostasis, which have the potential to influence the main erythrocytosis-associated pathways. We provide valuable theoretical information for deeper insight into possible mechanisms of disease development. This information can be also helpful to improve the current diagnostic solutions for patients with idiopathic erythrocytosis.

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Pathomechanisms in the Kidneys in Selected Protozoan Parasitic Infections

International Journal of Molecular Sciences ◽

10.3390/ijms22084209 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4209

Author(s):

Karolina Kot ◽

Natalia Łanocha-Arendarczyk ◽

Michał Ptak ◽

Aleksandra Łanocha ◽

Elżbieta Kalisińska ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Molecular Mechanisms ◽

Kidney Injury ◽

Therapeutic Interventions ◽

Parasitic Infections ◽

Injury Mechanisms ◽

Kidney Involvement ◽

Leishmania Spp ◽

Apoptosis Process ◽

Insight Into

Leishmaniasis, malaria, toxoplasmosis, and acanthamoebiasis are protozoan parasitic infections. They remain important contributors to the development of kidney disease, which is associated with increased patients’ morbidity and mortality. Kidney injury mechanisms are not fully understood in protozoan parasitic diseases, bringing major difficulties to specific therapeutic interventions. The aim of this review is to present the biochemical and molecular mechanisms in kidneys infected with Leishmania spp., Plasmodium spp., Toxoplasma gondii, and Acanthamoeba spp. We present available mechanisms of an immune response, oxidative stress, apoptosis process, hypoxia, biomarkers of renal injury in the serum or urine, and the histopathological changes of kidneys infected with the selected parasites. Pathomechanisms of Leishmania spp. and Plasmodium spp. infections have been deeply investigated, while Toxoplasma gondii and Acanthamoeba spp. infections in the kidneys are not well known yet. Deeper knowledge of kidney involvement in leishmaniasis and malaria by presenting their mechanisms provides insight into how to create novel and effective treatments. Additionally, the presented work shows gaps in the pathophysiology of renal toxoplasmosis and acanthamoebiasis, which need further research.

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The apple C2H2-type zinc finger transcription factor MdZAT10 positively regulates JA-induced leaf senescence by interacting with MdBT2

Horticulture Research ◽

10.1038/s41438-021-00593-0 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Kuo Yang ◽

Jian-Ping An ◽

Chong-Yang Li ◽

Xue-Na Shen ◽

Ya-Jing Liu ◽

...

Keyword(s):

Mass Spectrometry ◽

Transcription Factor ◽

Liquid Chromatography ◽

Zinc Finger ◽

Leaf Senescence ◽

Transcriptional Activity ◽

Molecular Mechanisms ◽

Liquid Chromatography Mass Spectrometry ◽

Zinc Finger Transcription Factor ◽

Insight Into

AbstractJasmonic acid (JA) plays an important role in regulating leaf senescence. However, the molecular mechanisms of leaf senescence in apple (Malus domestica) remain elusive. In this study, we found that MdZAT10, a C2H2-type zinc finger transcription factor (TF) in apple, markedly accelerates leaf senescence and increases the expression of senescence-related genes. To explore how MdZAT10 promotes leaf senescence, we carried out liquid chromatography/mass spectrometry screening. We found that MdABI5 physically interacts with MdZAT10. MdABI5, an important positive regulator of leaf senescence, significantly accelerated leaf senescence in apple. MdZAT10 was found to enhance the transcriptional activity of MdABI5 for MdNYC1 and MdNYE1, thus accelerating leaf senescence. In addition, we found that MdZAT10 expression was induced by methyl jasmonate (MeJA), which accelerated JA-induced leaf senescence. We also found that the JA-responsive protein MdBT2 directly interacts with MdZAT10 and reduces its protein stability through ubiquitination and degradation, thereby delaying MdZAT10-mediated leaf senescence. Taken together, our results provide new insight into the mechanisms by which MdZAT10 positively regulates JA-induced leaf senescence in apple.

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Cold-Active β-Galactosidases: Insight into Cold Adaption Mechanisms and Biotechnological Exploitation

Marine Drugs ◽

10.3390/md19010043 ◽

2021 ◽

Vol 19 (1) ◽

pp. 43

Author(s):

Marco Mangiagalli ◽

Marina Lotti

Keyword(s):

Low Temperature ◽

Molecular Mechanisms ◽

Building Blocks ◽

Cold Active ◽

Cold Adaption ◽

Glycosyl Donor ◽

Pharmaceutical Industries ◽

Biotechnological Processes ◽

Hydrolysis Of ◽

Insight Into

β-galactosidases (EC 3.2.1.23) catalyze the hydrolysis of β-galactosidic bonds in oligosaccharides and, under certain conditions, transfer a sugar moiety from a glycosyl donor to an acceptor. Cold-active β-galactosidases are identified in microorganisms endemic to permanently low-temperature environments. While mesophilic β-galactosidases are broadly studied and employed for biotechnological purposes, the cold-active enzymes are still scarcely explored, although they may prove very useful in biotechnological processes at low temperature. This review covers several issues related to cold-active β-galactosidases, including their classification, structure and molecular mechanisms of cold adaptation. Moreover, their applications are discussed, focusing on the production of lactose-free dairy products as well as on the valorization of cheese whey and the synthesis of glycosyl building blocks for the food, cosmetic and pharmaceutical industries.

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Integrated Insight into the Molecular Mechanisms of Spontaneous Abortion during Early Pregnancy in Pigs

International Journal of Molecular Sciences ◽

10.3390/ijms22126644 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6644

Author(s):

Xupeng Zang ◽

Ting Gu ◽

Wenjing Wang ◽

Chen Zhou ◽

Yue Ding ◽

...

Keyword(s):

Immune Response ◽

Spontaneous Abortion ◽

Molecular Mechanisms ◽

Gene Set Enrichment Analysis ◽

Differentially Expressed ◽

Gene Set ◽

Cerna Network ◽

Major Interest ◽

End Stage ◽

Insight Into

Due to the high rate of spontaneous abortion (SAB) in porcine pregnancy, there is a major interest and concern on commercial pig farming worldwide. Whereas the perturbed immune response at the maternal–fetal interface is an important mechanism associated with the spontaneous embryo loss in the early stages of implantation in porcine, data on the specific regulatory mechanism of the SAB at the end stage of the implantation remains scant. Therefore, we used high-throughput sequencing and bioinformatics tools to analyze the healthy and arresting endometrium on day 28 of pregnancy. We identified 639 differentially expressed lncRNAs (DELs) and 2357 differentially expressed genes (DEGs) at the end stage of implantation, and qRT-PCR was used to verify the sequencing data. Gene set variation analysis (GSVA), gene set enrichment analysis (GSEA), and immunohistochemistry analysis demonstrated weaker immune response activities in the arresting endometrium compared to the healthy one. Using the lasso regression analysis, we screened the DELs and constructed an immunological competitive endogenous RNA (ceRNA) network related to SAB, including 4 lncRNAs, 11 miRNAs, and 13 genes. In addition, Blast analysis showed the applicability of the constructed ceRNA network in different species, and subsequently determined HOXA-AS2 in pigs. Our study, for the first time, demonstrated that the SAB events at the end stages of implantation is associated with the regulation of immunobiological processes, and a specific molecular regulatory network was obtained. These novel findings may provide new insight into the possibility of increasing the litter size of sows, making pig breeding better and thus improving the efficiency of animal husbandry production.

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