A5023199603- RNA regulation and disease
- interferon and immune responses
- Endoplasmic Reticulum Stress and Disease
- RNA and protein synthesis mechanisms
- RNA Research and Splicing
- Circadian rhythm and melatonin
- Toxin Mechanisms and Immunotoxins
- Viral Infectious Diseases and Gene Expression in Insects
- CRISPR and Genetic Engineering
- Autophagy in Disease and Therapy
- Cancer-related molecular mechanisms research
- RNA Interference and Gene Delivery
- Free Radicals and Antioxidants
- Fungal and yeast genetics research
- Bacteriophages and microbial interactions
- Pancreatic function and diabetes
- Chemical Synthesis and Analysis
- Monoclonal and Polyclonal Antibodies Research
- Immunotherapy and Immune Responses
- Virus-based gene therapy research
- Cellular transport and secretion
- ATP Synthase and ATPases Research
- Light effects on plants
- Cytokine Signaling Pathways and Interactions
- Biochemical and Molecular Research
Princeton University
2013-2024
Howard Hughes Medical Institute
2007-2015
University of California, San Francisco
2010-2015
University of Chicago
2006-2008
Rosalind Franklin University of Medicine and Science
2008
Institute of Molecular Biology and Biophysics
2008
Lomonosov Moscow State University
2003-2004
Accumulation of misfolded proteins in the endoplasmic reticulum (ER) triggers unfolded protein response (UPR), an intracellular signaling pathway that adjusts folding capacity ER according to need. If homeostasis environment cannot be reestablished, cells commit apoptosis. The ER-resident transmembrane kinase-endoribonuclease inositol-requiring enzyme 1 (IRE1) is best characterized UPR signal transduction molecule. In yeast, Ire1 oligomerizes upon activation accumulation ER. Here we show...
Crossed Homodimer Our cells respond to infection by releasing interferons, which protect neighboring cells, in part through the cleavage of intracellular RNA a protein kinase family receptor, RNase L. L is activated 2′,5″-linked oligoadenylates (the second messenger 2-5 A), sensors pathogen- and damage-associated RNA. Han et al. (p. 1244 , published online 27 February) report crystal structures human complexes with A, nucleotides, an 18-nucleotide oligomer target.
Accumulation of misfolded proteins in the lumen endoplasmic reticulum (ER) activates unfolded protein response (UPR). Ire1, an ER-resident transmembrane kinase/RNase, senses folding status inside ER. When activated, Ire1 oligomerizes and trans-autophosphorylates, activating its RNase initiating a nonconventional mRNA splicing reaction. Splicing results production transcription factor Hac1 that induces UPR target genes; expression these genes restores ER homeostasis by increasing capacity...
ADAR1 isoforms are adenosine deaminases that edit and destabilize double-stranded RNA reducing its immunostimulatory activities. Mutation of leads to a severe neurodevelopmental inflammatory disease children, Aicardi-Goutiéres syndrome. In mice, Adar1 mutations embryonic lethal but rescued by mutation the Mda5 or Mavs genes, which function in IFN induction. However, specific regulated proteins responsible for pathogenic effects unknown. We show cell-lethal phenotype deletion human lung...
The human sensor of double-stranded RNA (dsRNA) oligoadenylate synthetase 1 (hOAS1) polymerizes ATP into 2',5'-linked iso-RNA (2-5A) involved in innate immunity, cell cycle, and differentiation. We report the crystal structure hOAS1 complex with dsRNA 2'-deoxy at 2.7 Å resolution, which reveals mechanism cytoplasmic recognition activation synthetases. Human OAS1 recognizes using a previously uncharacterized protein/RNA interface that forms via conformational change induced by binding dsRNA....
Mammalian cells respond to double-stranded RNA (dsRNA) by activating a translation-inhibiting endoribonuclease, RNase L. Consensus in the field indicates that L arrests protein synthesis degrading ribosomal RNAs (rRNAs) and messenger (mRNAs). However, here we provide evidence for different far more efficient mechanism. By sequencing abundant fragments generated human cells, identify site-specific cleavage of two groups noncoding RNAs: Y-RNAs, whose function is poorly understood, cytosolic...
Significance Double-stranded RNA (dsRNA) is a pathogen-associated molecular pattern that triggers the type-I interferon (IFN) response in mammalian cells. The IFN up-regulates several dsRNA sensors, including closely related oligoadenylate synthetases (OAS). functional roles of different surveillance are not understood. Here, we use X-ray crystallography and biochemistry to demonstrate human OAS1 OAS3 recognize molecules length. We show domain duplication accompanied by loss catalytic...
Nocturnin (NOCT) is a rhythmically expressed protein that regulates metabolism under the control of circadian clock. It has been proposed NOCT deadenylates and metabolic enzyme mRNAs. However, in contrast to other deadenylases, purified lacks deadenylase activity. To identify substrate NOCT, we conducted mass spectrometry screen report specifically directly converts dinucleotide NADP+ into NAD+ NADPH NADH. Further, demonstrate Drosophila ortholog, Curled, same enzymatic We obtained 2.7 Å...
The unfolded protein response (UPR) controls the folding capacity of endoplasmic reticulum (ER). Central to this signaling pathway is ER-resident bifunctional transmembrane kinase/endoribonuclease Ire1. endoribonuclease (RNase) domain Ire1 initiates a non-conventional mRNA splicing reaction, leading production transcription factor that UPR target genes. reaction an obligatory step signaling, yet its mechanism has remained poorly understood due absence substrate-bound crystal structures Ire1,...
Two ER membrane-resident transmembrane kinases, IRE1 and PERK, function as stress sensors in the unfolded protein response. also has an endoribonuclease activity, which initiates a non-conventional mRNA splicing reaction, while PERK phosphorylates eIF2α. We engineered potent small molecule, IPA, that binds to IRE1's ATP-binding pocket predisposes kinase domain oligomerization, activating its RNase. IPA inhibits but, paradoxically, activates it at low concentrations, resulting bell-shaped...
2',5'-linked oligoadenylates (2-5As) serve as conserved messengers of pathogen presence in the mammalian innate immune system. 2-5As induce self-association and activation RNase L, which cleaves cytosolic RNA promotes production interferons (IFNs) cytokines driven by transcription factors IRF-3 NF-κB. We report that human L is activated forming high-order complexes, reminiscent mode phylogenetically related transmembrane kinase/RNase Ire1 unfolded protein response. describe crystal...
Ire1 is a signal transduction protein in the endoplasmic reticulum (ER) membrane that serves to adjust protein-folding capacity of ER according needs cell. signals, transcriptional program, unfolded response (UPR) via coordinated action its kinase and RNase domains. In this study, we investigated how binding cofactors domain modulates activity. Our results suggest initially binds without activation domain. activated upon subsequent conformational rearrangement governed by chemical properties...
Double-stranded RNA (dsRNA) activates the innate immune system of mammalian cells and triggers intracellular decay by pseudokinase endoribonuclease RNase L. L protects from pathogens regulates cell growth differentiation destabilizing largely unknown targets. We developed an approach for transcriptome-wide profiling activity in human identified hundreds direct targets nontargets. show that this L-dependent selectively affects transcripts regulated microRNA (miR)-17/miR-29/miR-200 other miRs...
Insufficient protein-folding capacity in the endoplasmic reticulum (ER) induces unfolded protein response (UPR). In ER lumen, accumulation of proteins activates transmembrane ER-stress sensor Ire1 and drives its oligomerization. cytosol, recruits HAC1 mRNA, mediating non-conventional splicing. The spliced mRNA is translated into Hac1, key transcription activator UPR target genes that mitigate ER-stress. this study, we report oligomeric assembly ER-lumenal domain sufficient to drive...
Cells of all mammals recognize double-stranded RNA (dsRNA) as a foreign material. In response, they release interferons (IFNs) and activate ubiquitously expressed pseudokinase/endoribonuclease RNase L. L executes regulated decay halts global translation. Here, we developed biosensor for 2′,5′-oligoadenylate (2-5A), the natural activator Using this biosensor, found that 2-5A was acutely synthesized by cells in response to dsRNA sensing, which immediately triggered cellular cleavage arrested...
We identified a non-synonymous mutation in Oas2 (I405N), sensor of viral double-stranded RNA, from an ENU-mutagenesis screen designed to discover new genes involved mammary development. The caused post-partum failure lactation healthy mice with otherwise normally developed glands, characterized by greatly reduced milk protein synthesis coupled epithelial cell death, inhibition proliferation and robust interferon response. Expression mutant but not wild type cultured HC-11 or T47D cells...
All kingdoms of life produce essential nicotinamide dinucleotide NADP(H) using NAD kinases (NADKs). A panel published NADK structures from bacteria, eukaryotic cytosol, and yeast mitochondria revealed similar tetrameric enzymes. Here, we present the 2.8-Å structure human mitochondrial kinase NADK2 with a bound substrate, which is an exception to this uniformity, diverging both structurally biochemically NADKs. We show that harbors unique tetramer disruptor/dimerization e lement, conserved in...
Restrictocin is a site-specific endoribonuclease that inactivates ribosomes by cleaving the sarcin/ricin loop (SRL) of 23S−28S rRNA. Here we present kinetic and thermodynamic analysis SRL cleavage reaction based on monitoring RNA oligonucleotides (2−27-mers). binds to 27-mer model substrate (designated wild-type SRL) via electrostatic interactions form nonspecific ground state complex E:S. At pH 6.7, physical steps govern rate: reacts at partially diffusion-limited rate, faster-reacting SRL,...