LUBAC regulates ciliogenesis by promoting CP110 removal from the mother centriole

Primary cilia transduce diverse signals in embryonic development and adult tissues. Defective ciliogenesis results in a series of human disorders collectively known as ciliopathies. The CP110–CEP97 complex removal from the mother centriole is an early critical step for ciliogenesis, but the underlying mechanism for this step remains largely obscure. Here, we reveal that the linear ubiquitin chain assembly complex (LUBAC) plays an essential role in ciliogenesis by targeting the CP110–CEP97 complex. LUBAC specifically generates linear ubiquitin chains on CP110, which is required for CP110 removal from the mother centriole in ciliogenesis. We further identify that a pre-mRNA splicing factor, PRPF8, at the distal end of the mother centriole acts as the receptor of the linear ubiquitin chains to facilitate CP110 removal at the initial stage of ciliogenesis. Thus, our study reveals a direct mechanism of regulating CP110 removal in ciliogenesis and implicates the E3 ligase LUBAC as a potential therapy target of cilia-associated diseases, including ciliopathies and cancers.     

Building the Chordata Olfactory Receptor Database using more than 400,000 receptors annotated by Genome2OR

Olfactory receptors are poorly annotated for most genome-sequenced chordates.To address this deficiency,we developed a nhmmer-based olfactory receptor annotation tool Genome2OR(https://github.com/To Hanwei/Genome2OR.git),and used it to process 1,695 sequenced chordate genomes in the NCBI Assembly database as of January,2021.In total,765,248 olfactory receptor genes were annotated,with 404,426 functional genes and 360,822 pseudogenes,which represents a four-fold increase in the number of annotate...     

Metabolomics study of type 2 diabetes using ultra-performance LC-ESI/quadrupole-TOF high-definition MS coupled with pattern recognition methods

Type 2 diabetes (T2D), called the burden of the twenty-first century, is growing with an epidemic rate. Here, we explored the differences in metabolite concentrations between T2D patients and healthy volunteers. Metabolomics represents an emerging discipline concerned with comprehensive analysis of small molecule metabolites and provides a powerful approach to discover biomarkers in biological systems. The acquired data were analyzed by ultra-performance liquid chromatography–electrospray ionization/quadrupole time-of-flight high-definition mass spectrometry coupled with pattern recognition approach [principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA)] to identify potential disease-specific biomarkers. PCA showed satisfactory clustering between patients and healthy volunteers. Biomarkers reflected the biochemical events associated with early stages of T2D which were observed in PLS-DA loading plots. These urinary differential metabolites, such as adiponectin, acylcarnitines, citric acid, kynurenic acid, 3-indoxyl sulfate, urate, and glucose, were identified involving several key metabolic pathways such as taurine and hypotaurine metabolism; cysteine and methionine metabolism; valine, leucine, and isoleucine biosynthesis metabolism, etc. Our data suggest that robust metabolomics has the potential as a noninvasive strategy to evaluate the early diagnosis of T2D patients and provides new insight into pathophysiologic mechanisms and may enhance the understanding of its cause of disease.     

Antioxidant Effect of Phenelzine on MPP+-Induced Cell Viability Loss in Differentiated PC12 Cells

Phenelzine, deprenyl, and antioxidants (SOD, catalase, ascorbate, or rutin) reduced the loss of cell viability in differentiated PC12 cells treated with 250 M MPP⁺, whereas N-acetylcysteine and dithiothreitol did not inhibit cell death. Phenelzine reduced the condensation and fragmentation of nuclei caused by MPP⁺ in PC12 cells. Phenelzine and deprenyl prevented the MPP⁺-induced decrease in mitochondrial membrane potential, cytochrome c release, formation of reactive oxygen species, and depletion of GSH in PC12 cells. Phenelzine revealed a scavenging action on hydrogen peroxide and reduced the hydrogen peroxide–induced cell death in PC12 cells, whereas deprenyl did not depress the cytotoxic effect of hydrogen peroxide. Both compounds reduced the iron and EDTA-mediated degradation of 2-deoxy-d-ribose degradation. The results suggest that phenelzine attenuates the MPP⁺-induced viability loss in PC12 cells by reducing the alteration of mitochondrial membrane permeability that seems to be mediated by oxidative stress.     

Potential pathophysiological role of microRNA 193b-5p in human placentae from pregnancies complicated by preeclampsia and intrauterine growth restriction

Molecular Biology Reports - Preeclampsia (PE) and intrauterine growth restriction (IUGR) are pregnancy complications resulting from abnormal placental development. MicroRNAs can regulate placental...     

A Novel Eliminase from a Marine Bacterium That Degrades Hyaluronan and Chondroitin Sulfate

Lyases cleave glycosaminoglycans (GAGs) in an eliminative mechanism and are important tools for the structural analysis and oligosaccharide preparation of GAGs. Various GAG lyases have been identified from terrestrial but not marine organisms even though marine animals are rich in GAGs with unique structures and functions. Herein we isolated a novel GAG lyase for the first time from the marine bacterium Vibrio sp. FC509 and then recombinantly expressed and characterized it. It showed strong lyase activity toward hyaluronan (HA) and chondroitin sulfate (CS) and was designated as HA and CS lyase (HCLase). It exhibited the highest activities to both substrates at pH 8.0 and 0.5 m NaCl at 30 °C. Its activity toward HA was less sensitive to pH than its CS lyase activity. As with most other marine enzymes, HCLase is a halophilic enzyme and very stable at temperatures from 0 to 40 °C for up to 24 h, but its activity is independent of divalent metal ions. The specific activity of HCLase against HA and CS reached a markedly high level of hundreds of thousands units/mg of protein under optimum conditions. The HCLase-resistant tetrasaccharide Δ^4,5HexUAα1-3GalNAc(6-O-sulfate)β1-4GlcUA(2-O-sulfate)β1-3GalNAc(6-O-sulfate) was isolated from CS-D, the structure of which indicated that HCLase could not cleave the galactosaminidic linkage bound to 2-O-sulfated d-glucuronic acid (GlcUA) in CS chains. Site-directed mutagenesis indicated that HCLase may work via a catalytic mechanism in which Tyr-His acts as the Brønsted base and acid. Thus, the identification of HCLase provides a useful tool for HA- and CS-related research and applications.     

Proline Metabolism in Neurological and Psychiatric Disorders

Proline plays a multifaceted role in protein synthesis, redox balance, cell fate regulation, brain development, and other cellular and physiological processes. Here, we focus our review on proline metabolism in neurons, highlighting the role of dysregulated proline metabolism in neuronal dysfunction and consequently neurological and psychiatric disorders. We will discuss the association between genetic and protein function of enzymes in the proline pathway and the development of neurological and psychiatric disorders. We will conclude with a potential mechanism of proline metabolism in neuronal function and mental health.     

Structure of solid-supported lipid membrane probed by noble metal nanoparticle deposition

Direct deposition of a noble metal layer onto a solid-supported membrane was proposed as an indirect microscopy tool to visually observe different lipid phases that may develop in the lipid membrane. The method relied on the different permeability of the lipid membrane towards the incident atoms during deposition. Liquid state or structural defects such as phase boundaries, step ledges in a multi-lamellar stack, and pores permitted the metal atoms to penetrate and nucleate inside the membrane whereas rigid gel state was relatively impermeable to the incident atoms, thus enabling visualization of liquid phase or structural defects inside the gel state. Based on the proposed method, we demonstrated the phase states resulting from thermotropic transitions of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), dioleoylphosphatidylethanolamine (DOPE)/DPPC mixture, and 1,2-dioleoyl-3-trimethylammonium propane (DOTAP). Although the proposed method does not allow in-situ observation of equilibrium states, the method should be an excellent complementary tool for visualizing the lipid phases as the method can resolve fine structural details (up to tens of nanometer scale) as seen in the DPPC membrane while providing macroscopic images (up to several micrometers).