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The methyltransferases that belong to the SpoU-TrmD family contain trefoil knots in their backbone fold. Recent structural dynamic and binding analyses of both free and bound homologs indicate that the knot within the polypeptide backbone plays a significant role in the biological activity of the molecule. The knot loops form the S-adenosyl-methionine (SAM)-binding pocket as well as participate in SAM binding and catalysis. Knots contain both at once a stable core as well as moving parts that modulate long-range motions. Here, we sought to understand allosteric effects modulated by the knotted topology. Uncovering the residues that contribute to these changes and the functional aspects of these protein motions are essential to understanding the interplay between the knot, activation of the methyltransferase, and the implications in RNA interactions. The question we sought to address is as follows How does the knot, which constricts the backbone as well as forms the SAM-binding pocket with its three distinctive loops, affect the binding mechanism? Using a minimally tied trefoil protein as the framework for understanding the structure-function roles, we offer an unprecedented view of the conformational mechanics of the knot and its relationship to the activation of the ligand molecule. Focusing on the biophysical characterization of the knot region by NMR spectroscopy, we identify the SAM-binding region and observe changes in the dynamics of the loops that form the knot. Importantly, we also observe long-range allosteric changes in flanking helices consistent with winding/unwinding in helical propensity as the knot tightens to secure the SAM cofactor. Proteins and their interactions control a plethora of biological functions and enable life. Protein-protein interactions can be highly dynamic, involve proteins with different degrees of 'foldedness' and are often regulated trough an intricate network of post-translational modifications. Central parts of protein-protein networks are intrinsically disordered proteins (IDPs). IDPs act as regulatory interaction hubs, enabled by their flexible nature. They employ various modes of binding mechanisms, from folding upon ligand binding to formation of highly dynamic 'fuzzy' protein-protein complexes. Mutations or perturbations in regulation of IDPs are hallmarks of many diseases. Protein surfaces play key roles in protein-protein interactions. However, protein surfaces and protein surface accessibility are difficult to study experimentally. Nuclear Magnetic Resonance-based solvent paramagnetic relaxation enhancement (sPRE) can provide quantitative experimental information on protein surface accessibility, which can be further used to obtain distance information for structure determination, identification of interaction surfaces, conformational changes and identification of low-populated transient structure and long-range contacts in IDPs and dynamic protein-protein interactions. In this review, we present and discuss state-of the art sPRE techniques and their applications to investigate structure and dynamics of IDPs and protein-protein interactions. Finally, we provide an outline for potential future applications of the sPRE approach in combination with complementary techniques and modeling, to study novel paradigms, such as liquid-liquid phase separation, regulation of IDPs and protein-protein interactions by post-translational modifications, and targeting of disordered proteins. Surfactant protein B (SP-B) is essential in transferring surface-active phospholipids from membrane-based surfactant complexes into the alveolar air-liquid interface. This allows maintaining the mechanical stability of the surfactant film under high pressure at the end of expiration, therefore SP-B is crucial in lung function. Despite its necessity, the structure and the mechanism of lipid transfer by SP-B have remained poorly characterized. find more Earlier, we proposed higher order oligomerization of SP-B into ring-like supramolecular assemblies. In the present work, we used coarse-grained molecular dynamics simulations to elucidate how the ring-like oligomeric structure of SP-B determines its membrane binding and lipid transfer. In particular, we explored how SP-B interacts with specific surfactant lipids, and how consequently SP-B reorganizes its lipid environment to modulate the pulmonary surfactant structure and function. Based on these studies, there are specific lipid-protein interactions leading to perturbation and reorganization of pulmonary surfactant layers. Especially, we found compelling evidence that anionic phospholipids and cholesterol are needed or even crucial in the membrane binding and lipid transfer function of SP-B. Also, on the basis of the simulations, larger oligomers of SP-B catalyze lipid transfer between adjacent surfactant layers. Better understanding of the molecular mechanism of SP-B will help in the design of therapeutic SP-B-based preparations and novel treatments for fatal respiratory complications, such as the acute respiratory distress syndrome. The cylindrical chaperonin GroEL and its cofactor GroES mediate ATP-dependent protein folding in Escherichia coli by transiently encapsulating non-native substrate in a nano-cage formed by the GroEL ring cavity and the lid-shaped GroES. Mechanistic studies of GroEL/ES with heterologous protein substrates suggested that the chaperonin is inefficient, typically requiring multiple ATP-dependent encapsulation cycles with only a few percent of protein folded per cycle. Here we analyzed the spontaneous and chaperonin-assisted folding of the essential enzyme 5,10-methylenetetrahydrofolate reductase (MetF) of E. coli, an obligate GroEL/ES substrate. We found that MetF, a homotetramer of 33-kDa subunits with (β/α)8 TIM-barrel fold, populates a kinetically trapped folding intermediate(s) (MetF-I) upon dilution from denaturant that fails to convert to the native state, even in the absence of aggregation. GroEL/ES recognizes MetF-I and catalyzes rapid folding, with ~50% of protein folded in a single round of encapsulation. Analysis by hydrogen/deuterium exchange at peptide resolution showed that the MetF subunit folds to completion in the GroEL/ES nano-cage and binds its cofactor flavin adenine dinucleotide. Rapid folding required the net negative charge character of the wall of the chaperonin cavity. These findings reveal a remarkable capacity of GroEL/ES to catalyze folding of an endogenous substrate protein that would have coevolved with the chaperonin system. INTRODUCTION We evaluated pulmonary adverse events observed within 7 days after drug initiation in phase 1-3 studies of the anaplastic lymphoma kinase (ALK) inhibitor brigatinib. METHODS The phase 1/2 study enrolled patients with advanced malignancies (dose range, 30-300 mg qd), the phase 2 ALTA study treated patients with advanced ALK+ non-small cell lung cancer (NSCLC) post-crizotinib at either 90 mg qd or 90 mg qd for 7 days followed by 180 mg qd, and the phase 3 ALTA-1L study treated inhibitor-naive ALK+ NSCLC patients with brigatinib (90 mg → 180 mg qd) or crizotinib (250 mg bid). Early-onset pulmonary events (EOPEs) at least possibly associated with brigatinib were captured. RESULTS In phase 1/2, ALTA, and ALTA-1L, 8% (11/137), 6% (14/219), and 3% (4/136) of patients, respectively, had at least possible EOPEs on brigatinib, with frequency appearing to increase with starting dose. Across trials, at the 90-mg qd starting dose (alone or step-up dosing), 4.5% of patients (20/440) had at least possible events (median time to onset, 2 days). Twelve (3%) patients had grade ≥3 events leading to brigatinib discontinuation. Seven (1.5%) patients had grade 1-2 events and successfully continued brigatinib with or without brigatinib interruption and/or steroids/supplemental oxygen. In pooled analysis of these trials, occurrence of EOPEs was significantly associated with continuous 10-year increases in patient age in unadjusted logistic regression analysis and with ECOG performance status and number of prior regimens in multivariate regression. CONCLUSIONS Clinically apparent EOPEs can occur within days of commencing brigatinib in a subset of patients with NSCLC. Identifying clinical parameters associated with a higher risk of developing such events may help mitigate these events. Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. On the other hand, idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease showing a prevalence of 20 new cases per 100,000 persons per year. Despite differences in cellular origin and pathological phenotypes, LC and IPF are lung diseases that share common features, including hyperproliferation of specific cell types in the lung, involvement of epithelial-mesenchymal transition (EMT) and enhanced activity of signaling pathways, such as tissue growth factor (TGFB), epidermal growth factor (EGF), fibroblast growth factor (FGF), wingless secreted glycoprotein (WNT) signaling, among others. EMT is a process during which epithelial cells lose their cell polarity and cell-cell adhesion, and acquire migratory and invasive properties to become mesenchymal cells. EMT involves numerous morphological hallmarks of hyperproliferative diseases, like cell plasticity, resistance to apoptosis, dedifferentiation and proliferation, thereby playing a central role during organ fibrosis and cancer progression. EMT was considered as an "all-or-none" process. In contrast to these outdated dichotomist interpretations, recent reports suggest that EMT occurs gradually involving different epithelial cell intermediate states with mesenchyme-like characteristics. These cell intermediate states of EMT differ from each other in their cell plasticity, invasiveness and metastatic potential, which in turn are induced by signals from their microenvironment. EMT is regulated by several transcription factors (TFs), which are members of prominent families of master regulators of transcription. In addition, there is increasing evidence for the important contribution of noncoding RNAs (ncRNAs) to EMT. In our review we highlight articles dissecting the function of different ncRNAs subtypes and nuclear architecture in cell intermediate states of EMT, as well as their involvement in LC and IPF. Head and neck cancer (HNC) constitute 5% of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers.
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