-
Cell Jul 2016Cellular bodies such as P bodies and PML nuclear bodies (PML NBs) appear to be phase-separated liquids organized by multivalent interactions among proteins and RNA...
Cellular bodies such as P bodies and PML nuclear bodies (PML NBs) appear to be phase-separated liquids organized by multivalent interactions among proteins and RNA molecules. Although many components of various cellular bodies are known, general principles that define body composition are lacking. We modeled cellular bodies using several engineered multivalent proteins and RNA. In vitro and in cells, these scaffold molecules form phase-separated liquids that concentrate low valency client proteins. Clients partition differently depending on the ratio of scaffolds, with a sharp switch across the phase diagram diagonal. Composition can switch rapidly through changes in scaffold concentration or valency. Natural PML NBs and P bodies show analogous partitioning behavior, suggesting how their compositions could be controlled by levels of PML SUMOylation or cellular mRNA concentration, respectively. The data suggest a conceptual framework for considering the composition and control thereof of cellular bodies assembled through heterotypic multivalent interactions.
Topics: Amino Acid Motifs; Artificial Cells; Body Composition; Carrier Proteins; Cell Compartmentation; Cell Line; Cell Nucleus; Cytoplasm; Electrochemistry; HeLa Cells; Humans; In Vitro Techniques; Molecular Structure; Organelles; Polypyrimidine Tract-Binding Protein; Protein Engineering; Proteins; Ubiquitins; Yeasts
PubMed: 27374333
DOI: 10.1016/j.cell.2016.06.010 -
Redox Biology Sep 2023Vascular endothelial cells (ECs) senescence plays a crucial role in vascular aging that promotes the initiation and progression of cardiovascular disease. The mutation...
Vascular endothelial cells (ECs) senescence plays a crucial role in vascular aging that promotes the initiation and progression of cardiovascular disease. The mutation of Grb10-interacting GYF protein 2 (GIGYF2) is strongly associated with the pathogenesis of aging-related diseases, whereas its role in regulating ECs senescence and dysfunction still remains elusive. In this study, we found aberrant hyperexpression of GIGYF2 in senescent human ECs and aortas of old mice. Silencing GIGYF2 in senescent ECs suppressed eNOS-uncoupling, senescence, and endothelial dysfunction. Conversely, in nonsenescent cells, overexpressing GIGYF2 promoted eNOS-uncoupling, cellular senescence, endothelial dysfunction, and activation of the mTORC1-SK61 pathway, which were ablated by rapamycin or antioxidant N-Acetyl-l-cysteine (NAC). Transcriptome analysis revealed that staufen double-stranded RNA binding protein 1 (STAU1) is remarkably downregulated in the GIGYF2-depleted ECs. STAU1 depletion significantly attenuated GIGYF2-induced cellular senescence, dysfunction, and inflammation in young ECs. Furthermore, we disclosed that GIGYF2 acting as an RNA binding protein (RBP) enhances STAU1 mRNA stability, and that the intron region of the late endosomal/lysosomal adaptor MAPK and mTOR activator 4 (LAMTOR4) could bind to STAU1 protein to upregulate LAMTOR4 expression. Immunofluorescence staining showed that GIGYF2 overexpression promoted the translocation of mTORC1 to lysosome. In the mice model, GIGYF2 Cdh-Cre mice protected aged mice from aging-associated vascular endothelium-dependent relaxation and arterial stiffness. Our work discloses that GIGYF2 serving as an RBP enhances the mRNA stability of STAU1 that upregulates LAMTOR4 expression through binding with its intron region, which activates the mTORC1-S6K1 signaling via recruitment of mTORC1 to the lysosomal membrane, ultimately leading to ECs senescence, dysfunction, and vascular aging. Disrupting the GIGYF2-STAU1-mTORC1 signaling cascade may represent a promising therapeutic approach against vascular aging and aging-related cardiovascular diseases.
Topics: Animals; Humans; Mice; Aging; Carrier Proteins; Cellular Senescence; Cytoskeletal Proteins; Endothelial Cells; Guanine Nucleotide Exchange Factors; Mechanistic Target of Rapamycin Complex 1; RNA-Binding Proteins
PubMed: 37517320
DOI: 10.1016/j.redox.2023.102824 -
RNA Biology Feb 2021The RNA-binding protein LARP1 has generated interest in recent years for its role in the mTOR signalling cascade and its regulation of terminal oligopyrimidine (TOP)... (Review)
Review
The RNA-binding protein LARP1 has generated interest in recent years for its role in the mTOR signalling cascade and its regulation of terminal oligopyrimidine (TOP) mRNA translation. Paradoxically, some scientists have shown that LARP1 represses TOP translation while others that LARP1 activates it. Here, we present opinions from four leading scientists in the field to discuss these and other contradictory findings.
Topics: Animals; Autoantigens; Binding Sites; Carrier Proteins; Gene Expression Regulation; Humans; Multigene Family; Protein Binding; Protein Interaction Domains and Motifs; RNA; RNA Cleavage; RNA-Binding Proteins; Ribonucleoproteins; Signal Transduction; Substrate Specificity; SS-B Antigen
PubMed: 32233986
DOI: 10.1080/15476286.2020.1733787 -
Molecules (Basel, Switzerland) Oct 2022The molybdenum cofactor (Moco) is the active site prosthetic group found in numerous vitally important enzymes (Mo-enzymes), which predominantly catalyze 2 electron... (Review)
Review
The molybdenum cofactor (Moco) is the active site prosthetic group found in numerous vitally important enzymes (Mo-enzymes), which predominantly catalyze 2 electron transfer reactions. Moco is synthesized by an evolutionary old and highly conserved multi-step pathway, whereby the metal insertion reaction is the ultimate reaction step here. Moco and its intermediates are highly sensitive towards oxidative damage and considering this, they are believed to be permanently protein bound during synthesis and also after Moco maturation. In plants, a cellular Moco transfer and storage system was identified, which comprises proteins that are capable of Moco binding and release but do not possess a Moco-dependent enzymatic activity. The first protein described that exhibited these properties was the Moco carrier protein (MCP) from the green alga . However, MCPs and similar proteins have meanwhile been described in various plant species. This review will summarize the current knowledge of the cellular Moco distribution system.
Topics: Carrier Proteins; Catalytic Domain; Chlamydomonas reinhardtii; Coenzymes; Metalloproteins; Molybdenum; Molybdenum Cofactors; Plants
PubMed: 36235107
DOI: 10.3390/molecules27196571 -
The EMBO Journal Nov 2021The pyruvate kinase M2 isoform (PKM2) is preferentially expressed in cancer cells to regulate anabolic metabolism. Although PKM2 was recently reported to regulate lipid...
The pyruvate kinase M2 isoform (PKM2) is preferentially expressed in cancer cells to regulate anabolic metabolism. Although PKM2 was recently reported to regulate lipid homeostasis, the molecular mechanism remains unclear. Herein, we discovered an ER transmembrane protein 33 (TMEM33) as a downstream effector of PKM2 that regulates activation of SREBPs and lipid metabolism. Loss of PKM2 leads to up-regulation of TMEM33, which recruits RNF5, an E3 ligase, to promote SREBP-cleavage activating protein (SCAP) degradation. TMEM33 is transcriptionally regulated by nuclear factor erythroid 2-like 1 (NRF1), whose cleavage and activation are controlled by PKM2 levels. Total plasma cholesterol levels are elevated by either treatment with PKM2 tetramer-promoting agent TEPP-46 or by global PKM2 knockout in mice, highlighting the essential function of PKM2 in lipid metabolism. Although depletion of PKM2 decreases cancer cell growth, global PKM2 knockout accelerates allografted tumor growth. Together, our findings reveal the cell-autonomous and systemic effects of PKM2 in lipid homeostasis and carcinogenesis, as well as TMEM33 as a bona fide regulator of lipid metabolism.
Topics: Animals; Breast Neoplasms; Carrier Proteins; Cell Line, Tumor; Cholesterol; Female; Gene Expression Regulation, Neoplastic; Homeostasis; Humans; Intracellular Signaling Peptides and Proteins; Lipid Metabolism; Membrane Proteins; Mice, Knockout; Sterol Regulatory Element Binding Protein 1; Thyroid Hormones; Xenograft Model Antitumor Assays; Thyroid Hormone-Binding Proteins; Mice
PubMed: 34487377
DOI: 10.15252/embj.2021108065 -
Biological & Pharmaceutical Bulletin 2018
Topics: Amino Acid Transport Systems; Animals; Carrier Proteins; GABA Plasma Membrane Transport Proteins; Humans; Membrane Transport Proteins
PubMed: 30270316
DOI: 10.1248/bpb.b18-ctf4110 -
Acta Crystallographica. Section D,... Apr 2021Kinesin-binding protein (KBP) is an important selective inhibitor of specific kinesin family members and its genetic disruption causes Goldberg-Shprintzen syndrome....
Kinesin-binding protein (KBP) is an important selective inhibitor of specific kinesin family members and its genetic disruption causes Goldberg-Shprintzen syndrome. Cryo-electron microscopy (cryo-EM) has recently been used to reveal the structure of KBP alone (72 kDa) and in complex with the motor domain of the mitotic kinesin-12 KIF15 (110 kDa). KBP is an α-solenoid, tetratricopeptide-repeat protein that interacts with the microtubule-binding region of the kinesin motor domain and blocks microtubule attachment. Numerous challenges arose relating to the behavior of KBP and KBP-kinesin complexes during cryo-EM sample preparation. These included the partial denaturation of KBP by air-water interfaces, protein aggregation resulting from carbon interaction and preferential orientation. Sample preparation with a graphene oxide substrate enabled the eventual structure determination. Here, experiences with preparing these samples are detailed, bringing attention to some of the challenges and opportunities that are likely to arise from protein-surface interactions.
Topics: Carrier Proteins; Cryoelectron Microscopy; Humans; Kinesins; Models, Molecular; Protein Binding; Protein Domains
PubMed: 33825702
DOI: 10.1107/S2059798321001935 -
Endocrine Regulations May 2021µ-Crystallin is a NADPH-regulated thyroid hormone binding protein encoded by the gene in humans. It is primarily expressed in the brain, muscle, prostate, and kidney,... (Review)
Review
µ-Crystallin is a NADPH-regulated thyroid hormone binding protein encoded by the gene in humans. It is primarily expressed in the brain, muscle, prostate, and kidney, where it binds thyroid hormones, which regulate metabolism and thermogenesis. It also acts as a ketimine reductase in the lysine degradation pathway when it is not bound to thyroid hormone. Mutations in can result in non-syndromic deafness, while its aberrant expression, predominantly in the brain but also in other tissues, has been associated with psychiatric, neuromuscular, and inflammatory diseases. CRYM expression is highly variable in human skeletal muscle, with 15% of individuals expressing ≥13 fold more mRNA than the median level. Ablation of the gene in murine models results in the hypertrophy of fast twitch muscle fibers and an increase in fat mass of mice fed a high fat diet. Overexpression of in mice causes a shift in energy utilization away from glycolysis towards an increase in the catabolism of fat via β-oxidation, with commensurate changes of metabolically involved transcripts and proteins. The history, attributes, functions, and diseases associated with , an important modulator of metabolism, are reviewed.
Topics: Animals; Carrier Proteins; Crystallins; Humans; Membrane Proteins; Mental Disorders; Nervous System Diseases; Thyroid Hormones; mu-Crystallins; Thyroid Hormone-Binding Proteins
PubMed: 34020530
DOI: 10.2478/enr-2021-0011 -
International Journal of Molecular... Apr 2017Copper ions are needed in several steps of cancer progression. However, the underlying mechanisms, and involved copper-binding proteins, are mainly elusive. Since most... (Review)
Review
Copper ions are needed in several steps of cancer progression. However, the underlying mechanisms, and involved copper-binding proteins, are mainly elusive. Since most copper ions in the body (in and outside cells) are protein-bound, it is important to investigate what copper-binding proteins participate and, for these, how they are loaded with copper by copper transport proteins. Mechanistic information for how some copper-binding proteins, such as extracellular lysyl oxidase (LOX), play roles in cancer have been elucidated but there is still much to learn from a biophysical molecular viewpoint. Here we provide a summary of copper-binding proteins and discuss ones reported to have roles in cancer. We specifically focus on how copper-binding proteins such as mediator of cell motility 1 (MEMO1), LOX, LOX-like proteins, and secreted protein acidic and rich in cysteine (SPARC) modulate breast cancer from molecular and clinical aspects. Because of the importance of copper for invasion/migration processes, which are key components of cancer metastasis, further insights into the actions of copper-binding proteins may provide new targets to combat cancer.
Topics: Animals; Biological Transport; Breast Neoplasms; Carrier Proteins; Cell Proliferation; Cell Transformation, Neoplastic; Copper; Copper Transport Proteins; Female; Gene Expression Regulation, Neoplastic; Humans; Metallochaperones; Models, Biological; Molecular Chaperones; Neoplasm Metastasis; Neovascularization, Pathologic; Osteonectin; Oxidation-Reduction; Protein-Lysine 6-Oxidase
PubMed: 28425924
DOI: 10.3390/ijms18040871 -
The American Journal of Psychiatry Mar 2018
Topics: Antidepressive Agents; Carrier Proteins; Depression; Humans; Polymorphism, Single Nucleotide; Selective Serotonin Reuptake Inhibitors; Stress, Physiological; Treatment Outcome
PubMed: 29490496
DOI: 10.1176/appi.ajp.2018.18010059