Mitochondria undergo continuous cycles of fission and fusion to promote inheritance, regulate quality control, and mitigate organelle stress. More recently, this process of mitochondrial dynamics has been demonstrated to be highly sensitive to nutrient supply, ultimately conferring bioenergetic plasticity to the organelle. However, whether regulators of mitochondrial dynamics play a causative role

Resistance to the extended-spectrum cephalosporin ceftriaxone in the pathogenic bacteria Neisseria gonorrhoeae is conferred by mutations in penicillin-binding protein 2 (PBP2), the lethal target of the antibiotic, but how these mutations exert their effect at the molecular level is unclear. Using solution NMR, X-ray crystallography, and isothermal titration calorimetry, we report that wild-type PBP2

Bacterial signaling histidine kinases (HKs) have long been postulated to function exclusively through linear signal transduction chains. However, several HKs have recently been shown to form complex multikinase networks (MKNs). The most prominent MKN, involving the enzymes RetS and GacS, controls the switch between the motile and biofilm lifestyles in the pathogenic bacterium Pseudomonas aeruginosa

DNA methylation shows complex correlations with gene expression, and the role of promoter hypermethylation in repressing gene transcription has been well addressed. Emerging evidence indicates that gene body methylation promotes transcription; however, the underlying mechanisms remain to be further investigated. Here, using methylated DNA immunoprecipitation sequencing (MeDIP-seq), bisulfite genomic

Accumulation of α-synuclein is a main underlying pathological feature of Parkinson's disease (PD) and α-synucleinopathies, for which lowering expression of the α-synuclein gene (SNCA) is a potential therapeutic avenue. Using a cell-based luciferase reporter of SNCA expression we performed a quantitative high throughput screen (qHTS) of 155,885 compounds and identified A-443654, an inhibitor of the

Histone deacetylase 3 (HDAC3) plays an important role in signal-dependent transcription and is dysregulated in diseases such as cancer. Previous studies have shown that the function of HDAC3 requires an activation step, which is mediated by the interactions of HDAC3 with the deacetylase-activation domain (DAD) of nuclear receptor corepressors and inositol tetraphosphate (IP4). However, the role of

The human AAA ATPase p97, a potential target for cancer therapeutics, plays a vital role in the clearing of misfolded proteins. p97 dysfunction is also known to play a crucial role in several neurodegenerative disorders, such as MultiSystem Proteinopathy 1 (MSP-1) and Familial Amyotrophic Lateral Sclerosis (ALS). However, the structural basis of its role in such diseases remain elusive. Here, we present

The heterogeneity of respirable particulates and compounds complicates our understanding of transcriptional responses to air pollution. Here, we address this by applying precision nuclear run-on sequencing (PRO-seq) and the assay for transposase-accessible chromatin sequencing (ATAC-seq) to measure nascent transcription and chromatin accessibility in airway epithelial cells after wood smoke particle

African swine fever virus (ASFV) is a large DNA virus that is highly contagious and pathogenic in domestic pigs with a mortality rate up to 100%. However, how ASFV suppresses JAK-STAT1 signaling to evade the immune response remains unclear. In this study, we found that the ASFV-encoded protein MGF-505-7R inhibited proinflammatory IFN-γ-mediated JAK-STAT1 signaling. Mechanistically, MGF-505-7R was found

Autophagosome-lysosome pathway (ALP) insufficiency has been suggested to play a critical role in the pathogenesis of cardiac hypertrophy. However, the mechanisms underlying ALP insufficiency remain largely unknown, and strategies to specifically manipulate ALP insufficiency for treating cardiac hypertrophy are lacking. Transcription factor EB (TFEB), as a master regulator of ALP, regulates the generation

Reactive oxygen species are key factors that strongly affect the cellular redox state and regulate various physiological and cellular phenomena. To monitor changes in the redox state, we previously developed fluorescent redox sensors named Re-Q, the emissions of which are quenched under reduced conditions. However, such fluorescent probes are unsuitable for use in the cells of photosynthetic organisms

During vascular interventions, oxidized low-density lipoprotein (oxLDL) and lysophosphatidylcholine (lysoPC) accumulate at the site of arterial injury, inhibiting endothelial cell (EC) migration and arterial healing. LysoPC activates canonical transient receptor potential 6 (TRPC6) channels leading to a prolonged increase in intracellular calcium ion concentration ([Ca2+]i) that inhibits EC migration

SENP2 (Sentrin/SUMO-specific protease 2)-deficient mice develop spontaneous seizures in early life due to a marked reduction in M-currents, which regulate neuronal membrane excitability. We have previously shown that hyper-SUMOylation of the Kv7.2 and Kv7.3 channels is critically involved in the regulation of the M-currents conducted by these potassium voltage-gated channels. Here we show that hyper-SUMOylation

The deubiquitinating enzyme USP37 is known to contribute to timely onset of S-phase and progression of mitosis. However, it is not clear if USP37 is required beyond S-phase entry despite expression and activity of USP37 peaking within S-phase. We have utilized flow cytometry and microscopy to analyze populations of replicating cells labeled with thymidine analogs and monitored mitotic entry in synchronized

Very low-density lipoprotein receptor (VLDLR) is a multifunctional transmembrane protein. Beyond the function of the full-length VLDLR in lipid transport, the soluble ectodomain of VLDLR (sVLDLR) confers anti-inflammatory and anti-angiogenic roles in ocular tissues through inhibition of canonical Wnt signaling. However, it remains unknown how sVLDLR is shed into the extracellular space. In this study

We previously reported that dietary amino acid restriction induces the accumulation of triglycerides (TAG) in the liver of growing rats. However, differences in TAG accumulation in individual cell types or other tissues were not examined. In this study, we show that TAG also accumulates in the muscle and adipose tissues of rats fed a low amino acid (low-AA) diet. In addition, dietary lysine restriction

Cysteamine dioxygenase (ADO) plays a vital role in regulating thiol metabolism and preserving oxygen homeostasis in humans by oxidizing the sulfur of cysteamine and N-terminal cysteine-containing proteins to their corresponding sulfinic acids using O2 as a cosubstrate. However, as the only thiol dioxygenase that processes both small-molecule and protein substrates, how ADO handles diverse substrates

Molecular motors such as kinesin and myosin often work in groups to generate the directed movements and forces critical for many biological processes. Although much is known about how individual motors generate force and movement, surprisingly little is known about the mechanisms underlying the macroscopic mechanics generated by multiple motors. For example, the observation that a saturating number

Mitochondrial Ca2+ uptake tailors the strength of stimulation of plasma membrane phospholipase C-coupled receptors to that of cellular bioenergetics. However, how Ca2+ uptake by the mitochondrial Ca2+ uniporter (MCU) shapes receptor-evoked inter-organellar Ca2+ signaling is unknown. Here, we used CRISPR/Cas9 gene knockout, sub-cellular Ca2+ imaging and mathematical modeling to show that MCU is a universal

Histone arginine methylation is a key post-translational modification that mediates epigenetic events that activate or repress gene transcription. Protein arginine methyltransferases (PRMTs) are the driving force for the process of arginine methylation, and the core histone proteins have been shown to be substrates for most PRMT family members. However, previous reports of the enzymatic activities

The yeast endoplasmic reticulum has three distinct protein translocation channels. The heterotrimeric Sec61 and Ssh1 complexes, which bind translating ribosomes, mediate cotranslational translocation of proteins targeted to the endoplasmic reticulum by the signal recognition particle (SRP) and SRP receptor targeting pathway, whereas the heptameric Sec complex has been proposed to mediate ribosome-independent

Elevated intracellular levels of deoxy-nucleotide triphosphates (dNTPs) have been shown to be a biochemical marker of cancer cells. Recently, a series of mutations in the multi-functional dNTPase, SAMHD1, have been reported in various cancers. Here we investigated the structure and functions of SAMHD1 R366C/H mutants, found in colon cancer and leukemia. Unlike many other cancer-specific mutations,

Hibernation is an example of extreme hypometabolic behavior. How mammals achieve such a state of suspended animation remains unclear. Here we show that several strains of type 2 diabetic mice spontaneously enter into hibernation-like suspended animation (HLSA) in cold temperatures. Non-diabetic mice injected with ATP mimic the severe hypothermia analogous to that observed in diabetic mice. We identified

Collagens play important roles in development and homeostasis in most higher organisms. In order to function, collagens require the specific chaperone HSP47 for proper folding and secretion. HSP47 is known to bind to the collagen triple-helix but the exact positions and numbers of binding sites are not clear. Here, we employed a collagen II peptide library to characterize high-affinity binding sites

The bacterial insertion sequence (IS) IS26 mobilises and disseminates antibiotic resistance genes. It differs from bacterial IS that have been studied to date as it exclusively forms cointegrates via either a copy-in (replicative) or a recently-discovered targeted conservative mode. To investigate how the Tnp26 transposase recognises the 14 bp terminal inverted repeats (TIR) that bound the IS, amino

LysO, a prototypical member of the LysO family, mediates export of L-lysine (Lys) and resistance to the toxic Lys antimetabolite, L-thialysine (Thl) in E. coli. Here, we have addressed unknown aspects of LysO function pertaining to its membrane topology and the mechanism by which it mediates Lys / Thl export. Using substituted cysteine (Cys) accessibility, here we delineated the membrane topology of

ToxR represents an essential transcription factor of Vibrio cholerae, which is involved in the regulation of multiple, mainly virulence associated genes. Its versatile functionality as activator, respressor or co-activator suggests a complex regulatory mechanism, whose clarification is essential for a better understanding of the virulence expression system of V. cholerae. Here, we provide structural

Cyclin dependent kinase 7 (CDK7) is a master regulatory kinase that drives cell cycle progression and stimulates expression of oncogenes in a myriad of cancers. Inhibitors of CDK7 (CDK7i) are currently in clinical trials; however, as with many cancer therapies, patients will most likely experience recurrent disease due to acquired resistance. Identifying targets underlying CDK7i resistance will facilitate

Inactivation of p53 is present in almost every tumor and hence, p53-reactivation strategies are an important aspect of cancer therapy. Common mechanisms for p53 loss in cancer include expression of p53 negative regulators such as MDM2, which mediate the degradation of wild-type (WT) p53 (p53α), and inactivating mutations in the TP53 gene. Currently, approaches to overcome p53 deficiency in these cancers

In Alzheimer's Disease (AD), deposition of pathological Tau and Amyloid-β (Aβ) drive synaptic loss and cognitive decline. The injection of misfolded Tau aggregates extracted from human AD brains drives templated spreading of Tau pathology within wild type mouse brain. Here, we assessed the impact of Aß co-pathology, of deleting loci known to modify AD risk (Ptk2b, Grn, Tmem106b) and of pharmacological

Acylation modifications, such as the succinylation of lysine, are post-translational modifications and a powerful means of regulating protein activity. Some acylations occur nonenzymatically, driven by an increase in the concentration of acyl group donors. Lysine succinylation has a profound effect on the corresponding site within the protein, as it dramatically changes the charge of the residue. In

Cytochrome P450 27C1 (P450 27C1) is a retinoid desaturase expressed in the skin that catalyzes the formation of 3,4-dehydroretinoids from all-trans retinoids. Within the skin, retinoids are important regulators of proliferation and differentiation. In vivo, retinoids are bound to cellular retinol- and retinoic acid-binding proteins (CRBPs and CRABPs). Interaction with these binding proteins is a defining

In plasma, iron is normally bound to transferrin, the principal protein in blood responsible for binding and transporting iron throughout the body. However, in conditions of iron overload when the iron-binding capacity of transferrin is exceeded, non-transferrin-bound iron (NTBI) appears in plasma. NTBI is taken up by hepatocytes and other parenchymal cells via NTBI transporters and can cause cellular

Cell migration is an essential physiological process and aberrant migration of epithelial cells underlies many pathological conditions. However, the molecular mechanisms governing cell migration are not fully understood. We report here that growth factor-induced epithelial cell migration is critically dependent on the crosstalk of two molecular switches, namely phosphorylation-switch (P-switch) and

Pheromone receptors (PRs) recognize specific pheromone compounds to guide the behavioral outputs of insects, which are the most diverse group of animals on earth. The activation of PRs is known to couple to the calcium permeability of their coreceptor (Orco) or putatively with G proteins; however, the underlying mechanisms of this process are not yet fully understood. Moreover, whether this transverse

Tissue factor (TF) is the principal initiator of blood coagulation and is necessary for thrombosis. We previously reported that lysophosphatidic acid (LPA), a potent bioactive lipid, highly induces TF expression at the transcriptional level in vascular smooth muscle cells. To date, however, the specific role of the LPA receptor is unknown, and the intracellular signaling pathways that lead to LPA induction

The CD8αβ heterodimer plays a crucial role in the stabilisation between major histocompatibility complex class I molecules (MHC-I) and the T cell receptor (TCR). The interaction between CD8 and MHC-I can be regulated by post-translational modifications, which are proposed to play an important role in the development of CD8 T cells. One modification that has been proposed to control CD8 co-receptor

The parasite Trypanosoma brucei exists in both a bloodstream form (BSF) and a procyclic form (PCF), which exhibit large carbohydrate extensions on the N-linked glycans and glycosylphosphatidylinositol (GPI) anchors, respectively. The parasite's glycoconjugate repertoire suggests at least 38 glycosyltransferase (GT) activities, 16 of which are currently uncharacterized. Here, we probe the function(s)

Human endometrial stromal cells (ESCs) differentiate into decidual cells by the action of progesterone, which is essential for implantation and maintenance of pregnancy. We previously reported that glucose uptake by human endometrial stromal cells (ESCs) increases during decidualization and that glucose is indispensable for decidualization. Although glucose transporter 1 (GLUT1) is up-regulated during

The seasonal nature of outbreaks of respiratory viral infections with increased transmission during low temperatures has been well established. Accordingly, temperature has been suggested to play a role on the viability and transmissibility of SARS-CoV-2, the virus responsible for the COVID-19 pandemic. The receptor binding domain (RBD) of the Spike glycoprotein is known to bind to its host receptor

Chitin deacetylases (CDAs) are found in many different organisms ranging from marine bacteria to fungi and insects. These enzymes catalyze the removal of acetyl groups from chitinous substrates generating various chitosans, linear co- polymers consisting of N-acetylglucosamine (GlcNAc) and glucosamine (GlcN). CDAs influence the degree of acetylation (DA) of chitosans as well as their pattern of acetylation

Nitroreductases are emerging as attractive bioremediation enzymes, with substrate promiscuity toward both natural and synthetic compounds. Recently, the nitroreductase NfnB from Sphingopyxis sp. strain HMH exhibited metabolic activity for dinitroaniline herbicides including butralin and pendimethalin, triggering the initial steps of their degradation and detoxification. However, the determinants of

Bromodomains (BD) are conserved reader modules that bind acetylated lysine residues on histones. Although much has been learned regarding the in vitro properties of these domains, less is known about their function within chromatin complexes. SWI/SNF chromatin-remodeling complexes modulate transcription and contribute to DNA damage repair. Mutations in SWI/SNF subunits have been implicated in many

Metabolic flexibility is the capacity of cells to alter fuel metabolism in response to changes in metabolic demand or nutrient availability. It is critical for maintaining cellular bioenergetics and is involved in the pathogenesis of cardiovascular disease and metabolic disorders. However, the regulation and function of metabolic flexibility in lymphatic endothelial cells (LECs) remain unclear. We

The proper cellular response to DNA double-strand breaks (DSBs) is critical for maintaining the integrity of the genome. RecQL4, a DNA helicase of which mutations are associated with Rothmund-Thomson Syndrome (RTS), is required for the DNA DSB response. However, the mechanism by which RecQL4 performs these essential roles in the DSB response remains unknown. Here, we show that RecQL4 and its helicase

Huntington's disease (HD), a neurodegenerative disease characterized by progressive dementia, psychiatric problems, and chorea, is known to be caused by CAG repeat expansions in the HD gene HTT. However, the mechanism of this pathology is not fully understood. The translesion DNA polymerase θ (Polθ) carries a large insertion sequence in its catalytic domain, which has been shown to allow DNA loop-outs

Dimethyladenosine transferase 1 (DIMT1) is an evolutionarily conserved RNA N6,6-dimethyladenosine (m26,6A) methyltransferase. DIMT1 plays an important role in ribosome biogenesis, and the catalytic activity of DIMT1 is indispensable for cell viability and protein synthesis. A few RNA modifying enzymes can install the same modification in multiple RNA species. However, whether DIMT1 can work on RNA

Neuronal activity can enhance tau release and, thus accelerate tauopathies. This activity-dependent tau release can be used to study the progression of tau pathology in Alzheimer's disease (AD), as hyper-phosphorylated tau is implicated in AD pathogenesis and related tauopathies. However, our understanding of the mechanisms that regulate activity-dependent tau release from neurons and the role that

DNA-protein crosslinks are formed when proteins become covalently trapped with DNA in the presence of exogenous or endogenous alkylating agents. If left unrepaired, they inhibit transcription as well as DNA unwinding during replication, and may result in genome instability or even cell death. The DNA repair protein O6-alkylguanine DNA-alkyltransferase (AGT) is known to form DNA crosslinks in the presence

A number of human autoinflammatory diseases manifest with severe inflammatory bone destruction. Mouse models of these diseases represent valuable tools that help us to understand molecular mechanisms triggering this bone autoinflammation. The Pstpip2cmo mouse strain is among the best characterized of these; it harbors a mutation resulting in the loss of adaptor protein PSTPIP2 and development of autoinflammatory

Cells synthesize proteins using 20 standard amino acids and expand their biochemical repertoire through intricate enzyme-mediated post-translational modifications (PTMs). PTMs can either be static and represent protein editing events or be dynamically regulated as a part of a cellular response to specific stimuli. Protein histidine methylation (Hme) was an elusive PTM for over 5 decades and has only

Mass spectrometry imaging (MSI) is a powerful tool in drug discovery due its ability to interrogate a wide range of endogenous and exogenous molecules in a broad variety of samples. The impressive versatility of the approach, where almost any ionizable biomolecule can be analyzed, including peptides, proteins, lipids, carbohydrates, and nucleic acids, has been applied to numerous types of complex biological

Transient receptor (TRP) cation channels, which are conserved across mammals, flies, fish, sea squirts, worms, and fungi essentially contribute to cellular Ca2+ signalling. The activity of the unique TRP channel in yeast, TRPY1, relies on the vacuolar and cytoplasmic Ca2+ concentration. However, the mechanism(s) of Ca2+-dependent regulation of TRPY1 and possible contribution(s) of Ca2+-binding proteins

Lack of simple and robust methods to determine complement activation in human serum induced by antigen-antibody complexes is a major hurdle for monitoring therapeutic antibody drug quality and stability. Dezamizumab is a humanized IgG1 monoclonal antibody that binds to serum amyloid P component (SAP) for potential treatment of systemic amyloidosis. The mechanism of action of Dezamizumab includes the

The SARS-CoV-2 spike is the primary target of virus-neutralizing antibodies and critical to the development of effective vaccines against COVID-19. Here, we demonstrate that the prefusion-stabilized two-proline "S2P" spike -widely employed for laboratory work and clinical studies- unfolds when stored at 4 °C, physiological pH, as observed by electron microscopy (EM) and differential scanning calorimetry

TRPC channels, as important membrane proteins regulating intracellular calcium (Ca2+i) signaling, are involved in a variety of physiological and pathological processes. Activation and regulation of TRPC are more dependent on membrane or intracellular signals. However, how extracellular signals regulate TRPC6 function remains to be further investigated. Here, we suggest that two distinct small molecules

In most organisms, transition metal ions are necessary cofactors of ribonucleotide reductase (RNR), the enzyme responsible for biosynthesis of the 2'-deoxynucleotide building blocks of DNA. The metal ion generates an oxidant for an active site cysteine (Cys), yielding a thiyl radical that is necessary for initiation of catalysis in all RNRs. Class I enzymes, widespread in eukaryotes and aerobic microbes

Many natural polysaccharides have significant anti-cancer activity with low toxicity, but the complex chemical structures make in-depth studies of the involved mechanisms extremely difficult. The purpose of this study was to investigate the effect of the marine bacterial exopolysaccharide EPS11 on liver cancer metastasis to explore the underlying target protein and molecular mechanism. We found that

Yeast is a facultative anaerobe and uses diverse electron acceptors to maintain redox-regulated import of cysteine-rich precursors via the mitochondrial intermembrane space assembly (MIA) pathway. With the growing diversity of substrates utilizing the MIA pathway, understanding the capacity of the intermembrane space (IMS) to handle different types of stress is crucial. We used mass spectrometry to

ADAMTS13 is a multidomain metalloprotease for which until now only a single substrate has been identified. ADAMTS13 cleaves the polymeric force-sensor von Willebrand factor (VWF) that unfolds under shear stress and recruits platelets to sites of vascular injury. Shear force dependent cleavage at a single Tyr-Met peptide bond in the unfolded VWF A2 domain serves to reduce the size of VWF polymers in