UBE2M, an essential neddylation E2 enzyme, has been implicated in the pathogenesis of various diseases, including cancers, viral infections, and obesity. However, whether UBE2M is involved in the pathogenesis of bacterial sepsis remains unclear. In an Escherichia coli (E. coli)-induced sepsis mouse model, increased UBE2M expression in macrophages in liver and lung tissues postinfection was observed

Targeted protein degradation (TPD) mediated by PROTACs (proteolysis targeting chimeras) or molecular glues is an emerging therapeutic strategy. Despite greater than 600 E3 ligases and their associated components, a limited number have been deployed in TPD. Those commonly used include cereblon (CRBN) and von Hippel-Lindau tumor suppressor (VHL), which are expressed widely and for which high affinity

The Golgi stress response is an important cytoprotective system that enhances Golgi function in response to cellular demand, while cells damaged by prolonged Golgi stress undergo cell death. OSW-1, a natural compound with anticancer activity, potently inhibits OSBP that transports cholesterol and phosphatidylinositol-4-phosphate (PI4P) at contact sites between the endoplasmic reticulum and the Golgi

Human genetic disorders are often caused by mutations of compound heterozygosity, where each allele of the mutant gene harbors a different genetic lesion. However, studies of such mutations are hampered, due to the lack of an appropriate model. Here we describe a kinetic model of compound heterozygous variants in an obligate enzyme dimer that contains one mutation in one monomer and the other mutation

Ephexin proteins are guanine nucleotide exchange factors for the Rho GTPases. We reported that Ephexin4 regulates M-phase progression downstream of phosphorylated EphA2, a receptor-type tyrosine kinase, through RhoG activation; however, the regulation of Ephexin4 during M phase remains unknown. In this study, a novel Ephexin4 phosphorylation site was identified at Ser41, exclusively in M phase. Ephexin4

Prohibitins (PHBs) are ubiquitously expressed proteins in the mitochondrial inner membrane (MIM) that provide membrane scaffolds for both mitochondrial proteins and phospholipids. Eukaryotic PHB complexes contain two highly homologous PHB subunits, PHB1 and PHB2, which are involved in various cellular processes, including metabolic control through the regulation of mitochondrial dynamics and integrity

SARS-CoV-2 main protease (Mpro) autocatalytically releases itself out of the viral polyprotein to form a fully active mature dimer in a manner that is not fully understood. Here, we introduce several tools to help elucidate differences between cis (intramolecular) and trans (intermolecular) proteolytic processing and to evaluate inhibition of precursor Mpro. We found that many mutations at the P1 position

Neutrophils are a part of the innate immune system and produce reactive oxygen species (ROS) to extinguish pathogens. The major source of ROS in neutrophils is NADPH oxidase, which is fueled by NADPH generated via the pentose phosphate pathway; however, it is unclear how other accessory glucose metabolism pathways and mitochondrial activity influence the respiratory burst. We examined the temporal

The bacterium Geotalea uraniireducens, commonly found in uranium-contaminated environments, plays a key role in bioremediation strategies by converting the soluble hexavalent form of uranium (UVI) into less soluble forms (e.g. UIV.). While most of the reduction and concomitant precipitation of uranium occur outside the cells, there have been reports of important reduction processes taking place in

Polymorphic microbial immune evasion proteins dictate the pathogen species- or strain-specific virulence. Metals can impact how microbial proteins confer host-pathogen interactions, but whether this activity can be allelically variable is unclear. Here, we investigate the polymorphic CspZ protein of Lyme disease (LD) spirochete bacteria to assess the role of metals in protein-protein interaction. CspZ

The recently discovered microbiome-generated obesogen, δ-valerobetaine (5-(trimethylammonio)pentanoate), is a 5-carbon structural analogue of the carnitine precursor, γ-butyrobetaine. Here, we report that δ-valerobetaine is enzymatically hydroxylated by mammalian γ-butyrobetaine dioxygenase (BBOX) to form 3-hydroxy-5-(trimethylammonio)pentanoate, a 5-carbon analogue of carnitine, which we term homocarnitine

Cobalamin (Cbl) is an essential cofactor for methionine synthase (MS) and methylmalonyl-CoA mutase (MUT), but it must first undergo chemical processing for utilization in animals. In humans, this processing comprises β-axial ligand cleavage and Cbl reduction and is performed by the enzyme MMACHC (HsCblC). Although the functionality of CblC is well-understood in higher order organisms, little is known

Trypanosoma cruzi is a flagellated protozoan and the etiological agent of Chagas Disease, a neglected tropical disease described by Carlos Chagas in 1909 that remains without appropriate diagnostics and treatment. Throughout its life cycle, T. cruzi undergoes through many different environments, requiring adaptation of its metabolism to different nutrition sources. Recent studies have confirmed the

Hydrogenases are key enzymes forming or consuming hydrogen. The inactivation of these transition metal biocatalysts with oxygen limits their biotechnological applications. Oxygen-sensitive hydrogenases are distinguished from oxygen-insensitive (tolerant) ones by their initial hydrogen turnover rates influenced by oxygen. Several hydrogenases, such as the oxygen-sensitive bidirectional [NiFe] Hox hydrogenase

Mitochondria synthesize only a small set of their proteins on endogenous mitoribosomes. These particles differ in structure and composition from both their bacterial 70S ancestors and cytosolic 80S ribosomes. Recently published high resolution structures of the human mitoribosome revealed the presence of three [2Fe-2S] clusters in the small and large subunits. Each of these clusters is coordinated

The electrochemical potentials of redox-active proteins need to be tuned accurately to the correct values for proper biological function. Here we describe a diheme cytochrome c with high heme redox potentials of about +350 mV, despite having a large overall negative charge which typically reduces redox potentials. High resolution crystal structures, spectroelectrochemical measurements and high-end

Synaptic adhesion molecules are essential components of the synapse, yet the diversity of these molecules and their associated functions remain to be fully characterized. Extracellular leucine rich repeat and fibronectin type III domain containing 1 (ELFN1) is a postsynaptic adhesion molecule in the brain that has been increasingly implicated in human neurological disease. ELFN1 is best known for trans-synaptically

Metastasis is a major cause of fatality in hepatocellular carcinoma (HCC), although the precise mechanisms driving the metastatic process remain incompletely understood. In this study, we have made several important findings. Firstly, we have discovered that elevated activation-induced cytidine deaminase (AID) expression is positively correlated with Jagged 1 (JAG1) levels in clinically metastatic

Bile acids are signaling molecules with critical roles in cholesterol and lipid metabolism, achieved by regulating the transcriptional activity of the farnesoid X receptor (FXR, NR1H4), otherwise known as the bile acid receptor. Modifications to the C6 position of the steroidal core yield bile acid derivatives with 100x improved potency over endogenous bile acids. Prevailing hypotheses suggested increased

Epitope mapping is a technique employed to define the region of an antigen that elicits an immune response, providing crucial insight into the structural architecture of the antigen as well as epitope-paratope interactions. With this breadth of knowledge, immunotherapies, diagnostics, and vaccines are being developed with a rational and data-supported design. Traditional epitope mapping methods are

Imbalances in testicular iron levels are linked to compromised sperm production and male infertility. Iron regulatory proteins (IRP) 1 and 2 play crucial roles in cellular iron regulation. We investigated the role of IRP1 on spermatogenesis using Irp1-deficient mice (Irp1-/-). Histological analysis of the testis of Irp1-/- mice revealed hypospermatogenesis with a significant reduction in the number

Formins play crucial roles in actin polymerization by nucleating filaments and regulating their elongation. Formins bind the barbed ends of filaments via their dimeric FH2 domains, which step processively onto incoming actin subunits during elongation. Actin monomers can bind formin-bound barbed ends directly or undergo diffusion-mediated delivery through interactions with formin FH1 domains and profilin

O-GlcNAcylation, a modification of nucleocytoplasmic proteins in mammals, plays a critical role in various cellular processes. However, the interplay and their underlying mechanisms in chemotherapy-induced tumor regression between O-GlcNAcylation and pyroptosis, a form of programmed cell death associated with innate immunity, remains unclear. Here, we observed that during the etoposide-induced pyroptosis

The combination of CDK4/6 inhibitors (CDK4/6i) and endocrine therapy is the first-line therapy for ER+/Her2- breast cancer, however, the development of drug resistance limited the efficacy of the agents. Although activation of the IFN signaling pathway has been identified as a critical driver of intrinsic and acquired CDK4/6i resistance, it remains unknown how the IFN signaling pathway was activated

2-hydroxy acids are organic carboxylic acids ubiquitous in the living world and are important building blocks in organic synthesis. Recently, the lactate racemase (LarA) superfamily, a diverse superfamily of 2-hydroxy acid racemases and epimerases using the nickel-pincer nucleotide (NPN) cofactor, has been uncovered. In this study, we performed a taxonomic analysis of the LarA superfamily, showing

The chemokine CXCL12 and its two cognate receptors - CXCR4 and ACKR3 - are key players in various homeostatic and pathophysiological processes, including embryonic development, autoimmune diseases, tissue repair and cancer. Recent reports identified an interaction of CXCR4 and ACKR3 with receptor activity-modifying proteins (RAMPs), and RAMP3 has been shown to facilitate ACKR3's recycling properties

ATP8A2 is a P4-ATPase that actively flips phosphatidylserine and to a lesser extent phosphatidylethanolamine across cell membranes to generate and maintain transmembrane phospholipid asymmetry. The importance of this flippase is evident in the finding that loss-of- function mutations in ATP8A2 are known to cause the neurodevelopmental disease known as cerebellar ataxia, intellectual disability, and

Epithelial mesenchymal transition (EMT) of lens epithelial cells (LECs) is one of the most important pathogenic mechanisms in lens fibrotic disorders, and the regulatory mechanisms of EMT have not been fully understood. Here, we demonstrate that the cAMP-response element binding protein (CREB) can regulate lens EMT in a phosphorylation-dependent and -independent manners with dual mechanisms. First

Phosphate (Pi) homeostasis at the cellular level is crucial, requiring coordinated Pi uptake, storage, and export. However, the regulatory mechanisms, particularly those governing Pi export, remain elusive, despite their relevance to human diseases like primary familial brain calcification. While Xpr1, conserved across eukaryotes, is the only known Pi exporter, the existence of additional Pi exporting

Obesity is one of the main clinical characteristics associated with the heterogeneous genetic disorder Bardet-Biedl syndrome (BBS). Leucine zipper transcription factor like 1 (LZTFL1) is a member of the BBS gene family. Our work showed that Lztfl1knockout (LZKO) mice display the obesity phenotype as early as three months of age. Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate

Understanding the fundamental biochemical and metabolic requirements for the replication of coronaviruses within infected cells is of notable interest for the development of broad-based therapeutic strategies, given the likelihood of emergence of new pandemic-potential virus species, as well as future variants of SARS-CoV-2. Here we demonstrate members of the glutaminase family of enzymes (GLS and

Voltage-gated sodium (Nav) channels are transmembrane proteins that play crucial roles in the initiation and propagation of action potentials (APs) in excitable tissues such as the heart, muscles, and nerves. The distal ends of the four domain S6 segments of Nav channels contain hydrophobic residues, which form an intracellular gate. This gate allows Nav channels to control ion flux in excitable cells

The mammalian prion protein can form infectious, non-native, and protease resistant aggregates (PrPD), which cause lethal prion diseases like human Creutzfeldt-Jakob disease. PrPD seeds the formation of new infectious prions by interacting with and triggering the refolding of the normally soluble mammalian prion protein, PrPC, into more PrPD. Refolding of misfolded proteins in the cell is carried out

The human body is an intricate ensemble of prokaryotic and eukaryotic cells, and this coexistence relies on the interplay of many biotic and abiotic factors. The inhabiting microbial population has to maintain its physiological homeostasis under highly dynamic and often hostile host environments. While bacterial colonization primarily relies on the metabolic suitability for the niche, there are reports

Regulatory T cells (Tregs) are immune regulatory T cells that are vital for controlling inflammation. The role of Tregs in inflammatory diseases namely Psoriatic Arthritis (PsA) is still poorly understood. The underlying reason being a lack of robust unbiased analysis to test the immune regulatory phenotype of human Tregs. Here, we propose that checkpoint receptors can identify functional Tregs in

High levels of all-trans-retinal (atRAL) in the retina is considered to be responsible for the development of autosomal recessive Stargardt's disease (STGD1) and dry age-related macular degeneration (dAMD). Two bisretinoids, all-trans-retinal dimer (atRAL-dimer) and N-retinyl-N-retinylidene ethanolamine (A2E), form from the dimerization of atRAL in the retina but they possess much lower toxicity and

Hyperosmotic shock induces cytochrome c release and caspase-3 activation in Xenopus oocytes. Different signaling pathways engaged by osmostress converge on the mitochondria to trigger cell death. The mitogen activated protein kinases (MAPKs) JNK1-1 and JNK1-2 are early activated by hyperosmotic shock and sustained activation of both isoforms accelerates the apoptotic program. Indeed, sustained activation

Serine incorporator 5 (SER5) can be incorporated into HIV-1 virions to block viral entry by disrupting the envelope glycoprotein-mediated viral fusion to the plasma membrane. Recent studies suggest that SER5 also inhibits HIV-1 mRNA transcription and the subsequent progeny virion biogenesis. However, the underlying mechanisms through which SER5 antagonizes the viral transcription remain poorly understood

The relationship between membrane proteins and the lipid constituents of the membrane bilayer depends on finely-tuned atomic interactions, which itself depends on the precise distribution of amino acids within the 3D structure of the protein. In this regard, tryptophan (Trp), one of the least abundant amino acids, is found at higher levels in transmembrane proteins where it likely plays a role in helping

The sheer amplitude of biological actions of insulin-like growth factor I (IGF-1) affecting all type of cells in all tissues suggests a vast signaling landscape for this ubiquitous humoral signal. While the canonical signaling pathways primarily involve the Ras/MAPK and PI3K/AKT cascades, the evolutionary conservation of insulin-like peptides (ILPs) and their pathways hints at the potential for novel

The proteasome is considered an excellent drug target for many infectious diseases as well as cancer. Challenges with robust and safe supply of proteasomes from infectious agents, lack of structural information and complex pharmacology due to multiple active sites have hampered progress in the infectious disease space. We recombinantly expressed the proteasome of the protozoan parasite Trypanosoma

Histone proteins organize nuclear DNA in eukaryotic cells and play crucial roles in regulating chromatin structure and function. Histone variants are produced by distinct histone genes and are produced independently of their canonical counterparts throughout the cell cycle. Even though histone variants may differ by only one or a few amino acids relative to their canonical counterparts, these minor

Mutations in the E3 ubiquitin ligase parkin cause a familial form of Parkinson's disease (PD). Parkin and the mitochondrial kinase PINK1 assure quality control of mitochondria through selective autophagy of mitochondria (mitophagy). Whereas numerous parkin mutations have been functionally and structurally characterized, several PD mutations found in the catalytic Rcat domain of parkin remain poorly

Many cells spend a major part of their life in quiescence, a reversible state characterized by a distinct cellular organization and metabolism. In glucose-depleted quiescent yeast cells, there is a metabolic shift from glycolysis to mitochondrial respiration, and a large fraction of proteasomes are reorganized into cytoplasmic granules containing disassembled particles. Given these changes, the operation

β-Adrenergic signaling activates cAMP-dependent PKA, which regulates the activity of L-type voltage-gated calcium channels such as CaV1.2. Several PKA target sites in the C-terminal tail of CaV1.2 have been identified, and their phosphorylation has been suggested to increase currents in specific tissues or heterologous expression systems. However, augmentation of CaV1.2 currents in the heart is instead

The stimulus-response curve is usually modeled by the Hill function due to its simplicity and clear molecular mechanisms (Michaelis-Menten type of kinetics). Unfortunately, the mechanisms do not explain why the stimulus is ubiquitously measured by logarithmic dose rather than the dose itself and why the log(dose)-response curve possesses such fine properties as symmetry and wide adjustability. Here

A great deal of attention is being paid to strategies seeking to uncover the biology of the four-stranded nucleic acid structure G-quadruplex (G4) via their stabilization in cells with G4-specific ligands. The conventional definition of chemical biology implies that a complete assessment of G4 biology can only be achieved by implementing a complementary approach involving the destabilization of cellular

The pituitary gonadotropin luteinizing hormone (LH) is the primary stimulus for ovulation, luteal formation, and progesterone synthesis, regardless of species. Despite increased awareness of intracellular signaling events initiating the massive production of progesterone during the reproductive cycle and pregnancy, critical gaps exist in our knowledge of the metabolic and lipidomic pathways required

Rab23 is a member of the Rab family of small GTPases. It plays crucial roles in Hedgehog signaling, ciliary transport, and embryonic development. As a small GTPase, Rab23 cycles between the GDP-bound inactivated state and the GTP-bound activated state. Mutations in Rab23 are directly implicated in Carpenter syndrome, a development disorder characterized by deformed skulls, abnormal fingers or toes

The human CXC chemokine receptor 1 (CXCR1), a G protein-coupled receptor (GPCR), plays significant roles in inflammatory diseases and cancer. While CXCL8 is a well-established high-affinity ligand for CXCR1, there is no consensus regarding the binding ability of the other ELR+ chemokines (CXCL1-3 and CXCL5-8). Since research has predominantly focused on CXCL8-mediated CXCR1 signaling, insight into

Understanding the mechanisms behind MYC-driven oncogenic transformation could pave the way for identifying novel drug targets. This study explored the role of CREPT in MYC-induced malignancy by generating MYC-transformed mouse embryonic fibroblasts (MEFs) with conditional CREPT deletion. Our results demonstrated that the loss of CREPT significantly impaired MYC-induced colony formation and cell proliferation

Different types of deposits comprised of amyloid-β (Aβ) peptides are one of the pathological hallmarks of Alzheimer’s disease (AD) and novel methods that enable identification of a diversity of Aβ deposits during the AD continuum are essential for understanding the role of these aggregates during the pathogenesis. Herein, different combinations of five fluorescent thiophene-based ligands were used

The onset and progression of type 2 diabetes is linked to the accumulation and aggregation of human islet amyloid polypeptide (hIAPP) in the pancreas. Amyloid oligomers and fibrils formed as a result of such aggregation exert high cytotoxicity. Although some pieces of evidence suggest that lipids could alter the rate of hIAPP aggregation, the effect of lipids on the aggregation properties of this peptide

c-di-GMP is an important second messenger in bacteria regulating, for example motility, biofilm formation, cell wall biosynthesis, infectivity, and natural transformability. It binds to a multitude of intracellular receptors. This includes proteins containing general secretory pathway II (GSPII) domains such as the N-terminal domain of the Vibrio cholerae ATPase MshE (MshEN) which binds c-di-GMP with

The TNF-TNFR1 signaling pathway plays a pivotal role in regulating the balance between cell survival and cell death. Upon binding to TNF, plasma membrane-localized TNFR1 initiates survival signaling, whereas TNFR1 internalization promotes caspase-mediated apoptosis. We previously reported that the α2-6 sialylation of TNFR1 by the tumor-associated sialyltransferase ST6GAL1 diverts signaling toward survival

Synthetic inhibitors of the serine protease DPP9 activate the related NLRP1 and CARD8 inflammasomes and stimulate powerful innate immune responses. Thus, it seems plausible that a biomolecule similarly inhibits DPP9 and triggers inflammasome activation during infection, but one has not yet been discovered. Here, we wanted to identify and characterize DPP9-binding proteins to potentially uncover physiologically

Agonist-independent, or constitutive, activity is an integral feature of G protein-coupled receptors, but its relevance in pathophysiological settings is generally poorly explored. GPR35 is a therapeutic target in inflammatory diseases of the lower gut. In colonic organoids from a human GPR35a-expressing transgenic mouse line, the GPR35 inverse agonist CID-2745687 increased barrier permeability substantially

To contract, to deform, and remodel, the airway smooth muscle cell relies on dynamic changes in the structure of its mechanical force–bearing cytoskeleton. These alternate between a “fluid-like” (relaxed) state characterized by weak contractile protein–protein interactions within the cytoskeletal apparatus and a “solid-like” (contractile) state promoted by strong and highly organized molecular interactions

Histones are traditionally recognized for structuring nuclear architecture and regulating gene expression. Recent advances have revealed their roles in inflammation, coagulation, and immune responses, where they act as damage-associated molecular patterns. The mechanisms by which histones induce membrane leakage are not well understood, and certain cells, including endothelial cells and peritoneal

Dynamic disassembly and reconstruction of the nuclear lamina during entry and exit of mitosis, respectively, are pivotal steps in the proliferation of higher eukaryotic cells. Although numerous post-translational modifications of lamin proteins have been identified, key factors driving the nuclear lamina dynamics remain elusive. Here we identified CDK1-elicited phosphorylation sites on endogenous Lamin