Mechanism of increased tyrosine (Tyr(99)) phosphorylation of calmodulin during hypoxia in the cerebral cortex of newborn piglets: the role of nNOS-derived nitric oxide

An integrated network pharmacology approach to discover therapeutic mechanisms of Commiphora wightii for the treatment of Bell's palsy

Bell's palsy (BP) can result in facial paralysis. Inflammation or injury to the cranial nerves that regulate the facial muscles is primarily responsible for that disease. Commiphora wightii remains recognized as a cure for a few human ailments. This study focused on therapeutic phenomena of C. wightii for the treatment of Bell's palsy, utilizing the network drug discovery and molecular docking techniques. Active biological constituents of C. wightii were retrieved from literature and independent databases. Potential therapeutic targets (431) of 13 bioactive phytochemicals were fetched via SwissTargetPrediction tool. Putative intersecting targets (855) of Bell's palsy were computed through the DisGeNET and GeneCards datasets. Subsequently, by the analysis of potential shared targets (87) of C. wightii and Bell's palsy, a Venn diagram was drawn. DAVID database was used to evaluate gene functional annotations and enriched pathways that are involved in Bell's palsy. STRING database was used for generating the protein-protein relationship complex. Visual presentations of the interactions of potential targets to active chemical constituents were done by the Cytoscape. Whereas, the conformational research sorted out 10 key targets through the protein-protein interactions network. Moreover, the capacity of therapeutic ingredients to interact with a target inhibiting Bell's palsy was confirmed by molecular docking, which might ratify the findings of network pharmacology. In the molecular complex of AKT1-cholesterol, a 100-ns simulation unveiled a graceful stability, with a minimal 0.167 Å ligand shift and resilient hydrogen bonds (ASN54 and SER205). The final 20 ns showcased a P1 motif pirouette, gracefully forming aromatic bonds with H165 and W186, underscoring the complex's dynamic finesse. This study evaluated compound-target interactions and their impact on disease-related genes. It revealed that five genes (AKT1, TNF, MAPK3, EGFR and SRC) of C. wightii might be useful therapeutic targets for the treatment of Bell's palsy, as well as helping in lowering down the blood pressure.Communicated by Ramaswamy H. Sarma.

Calmodulin: The switch button of calcium signaling

Calmodulin (CaM), a calcium sensor, decodes the critical calcium-dependent signals and converts them into the driving force to control various important cellular functions, such as ion transport. This small protein has a short central linker to connect two globular lobes and each unit is composed of a pair of homologous domains (HD) which are responsible for calcium binding. The conformation of each HD is sensitive to the levels of the intracellular Ca²⁺ concentrations while the flexible structure of the central domain enables its interactions with hundreds of cellular proteins. Apart from calcium binding, posttranslational modifications (PTMs) also contribute to the modulations of CaM functions by affecting its protein-protein interaction networks and hence drawing out the various downstream signaling cascades. In this mini-review, we first aim to elucidate the structural features of CaM and then overview the recent studies on the engagements of calcium binding and PTMs in Ca²⁺/CaM-mediated conformational alterations and signaling events. The mechanistic understanding of CaM working models is expected to be a key to decipher the precise role of CaM in cardiac physiology and disease pathology.

Flavopiridol (Alvocidib), a Cyclin-dependent Kinases (CDKs) Inhibitor, Found Synergy Effects with Niclosamide in Cutaneous T-cell Lymphoma

Flavopiridol (FVP; Alvocidib), a CDKs inhibitor, is currently undergoing clinical trials for treatment of leukemia and other blood cancers. Our studies demonstrated that FVP also inhibited p38 kinases activities with IC₅₀ (μM) for p38α: 1.34; p38 β: 1.82; p38γ: 0.65, and p38δ: 0.45. FVP showed potent cytotoxicity in cutaneous T-cell lymphoma (CTCL) Hut78 cells, with IC₅₀ <100 nM. NMR analysis revealed that FVP bound to p38γ in the ATP binding pocket, causing allosteric perturbation from sites surrounding the ATP binding pocket. Kinomic profiling with the PamGene platform in both cell-based and cell-free analysis further revealed dosage of FVP significantly affects downstream pathways in treated CTCL cells, which suggested a need for development of synergistic drugs with FVP to prevent its clinically adverse effects. It led us discover niclosamide as a synergistic drug of FVP for our future in vivo study.

The multifunctional role of phospho-calmodulin in pathophysiological processes

Calmodulin (CaM) is a versatile Ca²⁺-sensor/transducer protein that modulates hundreds of enzymes, channels, transport systems, transcription factors, adaptors and other structural proteins, controlling in this manner multiple cellular functions. In addition to its capacity to regulate target proteins in a Ca²⁺-dependent and Ca²⁺-independent manner, the posttranslational phosphorylation of CaM by diverse Ser/Thr- and Tyr-protein kinases has been recognized as an important additional manner to regulate this protein by fine-tuning its functionality. In this review, we shall cover developments done in recent years in which phospho-CaM has been implicated in signalling pathways that are relevant for the onset and progression of diverse pathophysiological processes. These include diverse systems playing a major role in carcinogenesis and tumour development, prion-induced encephalopathies and brain hypoxia, melatonin-regulated neuroendocrine disorders, hypertension, and heavy metal-induced cell toxicity.

Protein information content resides in rare peptide segments

Discovering the informational rule(s) underlying structure-function relationships in the protein language is at the core of biology. Current theories have proven inadequate to explain the origins of biological information such as that found in nucleotide and amino acid sequences. Here, we demonstrate that the information content of an amino acid motif correlates with the motif rarity. A structured analysis of the scientific literature supports the theory that rare pentapeptide words have higher significance than more common pentapeptides in biological cell 'talk'. This study expands on our previous research showing that the immunological information contained in an amino acid sequence is inversely related to the sequence frequency in the host proteome.