Abstract:
:The defining feature of the mycobacterial outer membrane (OM) is the presence of mycolic acids (MAs), which, in part, render the bilayer extremely hydrophobic and impermeable to external insults, including many antibiotics. Although the biosynthetic pathway of MAs is well studied, the mechanism(s) by which these lipids are transported across the cell envelope is(are) much less known. Mycobacterial membrane protein Large 3 (MmpL3), an essential inner membrane (IM) protein, is implicated in MA transport, but its exact function has not been elucidated. It is believed to be the cellular target of several antimycobacterial compounds; however, evidence for direct inhibition of MmpL3 activity is also lacking. Here, we establish that MmpL3 is the MA flippase at the IM of mycobacteria and is the molecular target of BM212, a 1,5-diarylpyrrole compound. We develop assays that selectively access mycolates on the surface of Mycobacterium smegmatis spheroplasts, allowing us to monitor flipping of MAs across the IM. Using these assays, we establish the mechanism of action of BM212 as a potent MmpL3 inhibitor, and use it as a molecular probe to demonstrate the requirement for functional MmpL3 in the transport of MAs across the IM. Finally, we show that BM212 binds MmpL3 directly and inhibits its activity. Our work provides fundamental insights into OM biogenesis and MA transport in mycobacteria. Furthermore, our assays serve as an important platform for accelerating the validation of small molecules that target MmpL3, and their development as future antituberculosis drugs.
journal_name
Proc Natl Acad Sci U S Aauthors
Xu Z,Meshcheryakov VA,Poce G,Chng SSdoi
10.1073/pnas.1700062114subject
Has Abstractpub_date
2017-07-25 00:00:00pages
7993-7998issue
30eissn
0027-8424issn
1091-6490pii
1700062114journal_volume
114pub_type
杂志文章abstract::A readily accessible new class of near infrared (NIR) molecular probes has been synthesized and evaluated. Specific fluorophores in this unique xanthene based regioisomeric seminaphthofluorone dye series exhibit a combination of desirable characteristics including (i) low molecular weight (339 amu), (ii) aqueous solub...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0710341105
更新日期:2008-07-01 00:00:00
abstract::A densely packed granular system is an example of an out-of-equilibrium system in the jammed state. It has been a longstanding problem to determine whether this class of systems can be described by concepts arising from equilibrium statistical mechanics, such as an effective temperature and compactivity. The measureme...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0409911102
更新日期:2005-02-15 00:00:00
abstract::Electrophysiological mapping of chronic atrial fibrillation (AF) at high throughput and high resolution is critical for understanding its underlying mechanism and guiding definitive treatment such as cardiac ablation, but current electrophysiological tools are limited by either low spatial resolution or electromechani...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2000207117
更新日期:2020-06-30 00:00:00
abstract::BSC-1 cells, epithelial cells of African green monkey kidney origin, show pronounced density-dependent regulation of growth in cell culture. Growth of the cells is rapid to a density of approximately 1.5 x 10(5) cells/per cm(2) in Dulbecco-modified Eagle's medium supplemented with 10% calf serum. Above this "saturatio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.1.339
更新日期:1978-01-01 00:00:00
abstract::The boreal forests, identified as a critical "tipping element" of the Earth's climate system, play a critical role in the global carbon budget. Recent findings have suggested that terrestrial carbon sinks in northern high-latitude regions are weakening, but there has been little observational evidence to support the i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1111576109
更新日期:2012-02-14 00:00:00
abstract::We have measured the angle-resolved transverse resistivity (ARTR), a sensitive indicator of electronic anisotropy, in high-quality thin films of the unconventional superconductor Sr2RuO4 grown on various substrates. The ARTR signal, heralding the electronic nematicity or a large nematic susceptibility, is present and ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1921713117
更新日期:2020-05-19 00:00:00
abstract::RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process that has evolved as an antiviral defense mechanism in plants and animals. It is not known whether host cells also use siRNAs as an antibacterial defense mechanism in eukaryotes. Here, we report the discovery of an endogeno...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0608258103
更新日期:2006-11-21 00:00:00
abstract::Electrical stimulation of the cervical vagus nerve in anesthetized guinea pigs induced a rapid increase in respiratory insufflation pressure, suggesting increased airway resistance. After intravenous administration of a substance P (SP) antagonist, [D-Arg(1),D-Pro(2),D-Trp(7,9),Leu(11)]SP, the insufflation pressure re...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.4.1120
更新日期:1983-02-01 00:00:00
abstract::The beta-globin locus control region (LCR) consists of four erythroid-specific DNase I-hypersensitive sites, which are necessary for high-level expression of the beta-like globin genes in erythroid tissues. One of these sites, designated 5'HS-2, functions as an erythroid-specific enhancer element in transfection and t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.9.3899
更新日期:1992-05-01 00:00:00
abstract::The actin cytoskeleton is a critical regulator of cytoplasmic architecture and mechanics, essential in a myriad of physiological processes. Here we demonstrate a liquid phase of actin filaments in the presence of the physiological cross-linker, filamin. Filamin condenses short actin filaments into spindle-shaped dropl...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1616133114
更新日期:2017-02-28 00:00:00
abstract::The somatostatin receptor subtype 2 (sst2) behaves as a tumor suppressor when expressed and stimulated by its ligand somatostatin in pancreatic cancer. We reveal a mechanism underlying oncosuppressive action of sst2, whereby this inhibitory receptor upregulates the expression of the secreted angioinhibitory factor thr...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0908674106
更新日期:2009-10-20 00:00:00
abstract::The ubiquitin-conjugating enzyme Ubc13 mediates lysine-63-specific protein ubiquitination involved in signal transduction by immune receptors; however, the in vivo physiological functions of Ubc13 remain incompletely understood. Using Ubc13 conditional knockout mice, we show that somatic deletion of the Ubc13 gene cau...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0906547106
更新日期:2009-12-08 00:00:00
abstract::The mechanisms for plant growth restriction during stress conditions remains unclear. Here, we demonstrate that a phytochrome-interacting factor-like protein, OsPIL1/OsPIL13, acts as a key regulator of reduced internode elongation in rice under drought conditions. The level of OsPIL1 mRNA in rice seedlings grown under...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1207324109
更新日期:2012-09-25 00:00:00
abstract::The image that best expresses Darwin's thinking is the tree of life. However, Darwin's human evolutionary tree lacked almost everything because only the Neanderthals were known at the time and they were considered one extreme expression of our own species. Darwin believed that the root of the human tree was very deep ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0914614107
更新日期:2010-05-11 00:00:00
abstract::We used positron emission tomography (PET) to examine the role of the hippocampal formation in implicit and explicit memory. Human volunteers studied a list of familiar words, and then they either provided the first word that came to mind in response to three-letter cues (implicit memory) or tried to recall studied wo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.1.321
更新日期:1996-01-09 00:00:00
abstract::It is possible, by using Fourier-transform infrared (FTIR) difference spectroscopy, to detect the conformational changes occurring in both the protein and the chromophore of bacteriorhodopsin during the photocycle. In contrast to Raman spectroscopy, a laser is unnecessary and hence the problem of a perturbing probe be...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.13.4045
更新日期:1982-07-01 00:00:00
abstract::We have established a transformation system for Dictyostelium discoideum. The transformation vector contains the protein coding region of the Tn5 neomycin resistance gene fused to the proposed promoter of the Dictyostelium actin 8 gene; the vector also contains a sequence that acts as an autonomously replicating seque...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.23.7356
更新日期:1982-12-01 00:00:00
abstract::Reactions of a membrane-bound multienzyme complex (electron-transport chain of rat-liver microsomes) suspended in aqueous-organic solvent used as antifreeze at temperatures below 0 degrees were studied. In the presence of a relatively high concentration of ethylene glycol, electron transfer can still be observed and s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.70.9.2633
更新日期:1973-09-01 00:00:00
abstract::ATM (ataxia-telangiectasia mutated) and ATR (ATM and Rad3-related) are large PI3 kinases whose human mutations result in complex syndromes that include a compromised DNA damage response (DDR) and prominent nervous system phenotypes. Both proteins are nuclear-localized in keeping with their DDR functions, yet both are ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1716892115
更新日期:2018-01-09 00:00:00
abstract::We used Monte Carlo methods to treat statistical problem of electrostatic interactions among many titrating amino acids and applied these methods to lysozyme and the photosynthetic reaction center of Rhodobacter sphaeroides, including all titrating sites. We computed the average protonation of residues as a function o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.13.5804
更新日期:1991-07-01 00:00:00
abstract::Serum amyloid A (SAA) is an acute-phase plasma protein that functions in innate immunity and lipid homeostasis. SAA is a protein precursor of reactive AA amyloidosis, the major complication of chronic inflammation and one of the most common human systemic amyloid diseases worldwide. Most circulating SAA is protected f...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1707120114
更新日期:2017-08-08 00:00:00
abstract::To achieve the mission of personalized medicine, centering on delivering the right drug to the right patient at the right dose, therapeutic drug monitoring solutions are necessary. In that regard, wearable biosensing technologies, capable of tracking drug pharmacokinetics in noninvasively retrievable biofluids (e.g., ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2009979117
更新日期:2020-08-11 00:00:00
abstract::The constant heavy chain (CH1) domain affects antibody affinity and fine specificity, challenging the paradigm that only variable regions contribute to antigen binding. To investigate the role of the CH1 domain, we constructed IgA2 from the broadly neutralizing anti-HIV-1 2F5 IgG1, and compared 2F5 IgA2 and IgG bindin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1200024109
更新日期:2012-07-31 00:00:00
abstract::Friend murine leukemia virus (F-MuLV) is a replication-competent retrovirus that induces a rapidly fetal leukemia in susceptible mice (stage I disease). Leukemia cells obtained from these animals do not grow in cell culture using standard tissue culture conditions. However, in the presence of WEHI-3 cell-conditioned m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.17.5464
更新日期:1984-09-01 00:00:00
abstract::The immunoglobulin heavy-chain variable region (VH) locus in a phylogenetically primitive teleost (Elops saurus) has been characterized by a strategy that relied initially on cross-hybridization between genomic VH segments and a murine VH probe. Using a homologous (Elops) VH probe and DNA sequencing, this gene family ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.2.811
更新日期:1990-01-01 00:00:00
abstract::Idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia is a ravaging condition of progressive lung scarring and destruction. Anti-inflammatory therapies including corticosteroids have limited efficacy in this ultimately fatal disorder. An important unmet need is to identify new agents that interact with key ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1001520107
更新日期:2010-08-10 00:00:00
abstract::The mutation spectrum induced by the widely used antitumor drug cis-diamminedichloroplatinum(II) (cis-DDP) showed that cisDDP[d(ApG)] adducts, although they account for only 25% of the lesions formed, are approximately 5 times more mutagenic than the major GG adduct. We report the construction of vectors bearing a sin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.16.6087
更新日期:1990-08-01 00:00:00
abstract::Throughout three domains of life, alanyl-tRNA synthetases (AlaRSs) recognize a G3:U70 base pair in the acceptor stem of tRNAAla as the major identity determinant of tRNAAla The crystal structure of the archaeon Archaeoglobus fulgidus AlaRS in complex with tRNAAla provided the basis for G3:U70 recognition with residues...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1807109115
更新日期:2018-07-17 00:00:00
abstract::We identified the phosphatidylinositol transfer protein (PITP) as being responsible for a powerful latent, nucleotide-independent, Golgi-vesiculating activity that is present in the cytosol but is only manifested as an uncontrolled activity in a cytosolic protein subfraction, in which it is separated from regulatory c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.19.11181
更新日期:1998-09-15 00:00:00
abstract::The alternative adaptive immune system of jawless vertebrates is based on different isotypes of variable lymphocyte receptors (VLRs) that are composed of leucine-rich repeats (LRRs) and expressed by distinct B- and T-like lymphocyte lineages. VLRB is expressed by B-like cells, whereas VLRA and VLRC are expressed by tw...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1415655111
更新日期:2014-10-14 00:00:00