Abstract:
:Legionella pneumophila is an intracellular parasite of freshwater protozoa and human macrophages. Recent studies determined that the macrophage infectivity potentiator (Mip) surface protein, a prokaryotic homolog of the FK506-binding proteins, is required for optimal infection of macrophages. To determine whether Mip is also involved in L. pneumophila infection of protozoa, we examined the ability of a strain lacking Mip to parasitize Hartmannella amoebae and Tetrahymena ciliates. After 3 days of incubation, approximately 1000-fold fewer bacteria were recovered from protozoan cocultures infected with the Mip- strain than from those cocultures infected with an isogenic Mip+ strain. The mip mutant was, however, not impaired in its ability to bind to amoebae cell surfaces, indicating that Mip is involved in bacterial resistance to intracellular killing and/or intracellular multiplication. These data suggest that L. pneumophila employs similar genes and mechanisms to infect human cells and protozoa. Furthermore, they support the hypothesis that the ability of L. pneumophila to parasitize macrophages and hence to cause human disease is a consequence of its prior adaptation to intracellular growth within protozoa.
journal_name
Proc Natl Acad Sci U S Aauthors
Cianciotto NP,Fields BSdoi
10.1073/pnas.89.11.5188keywords:
subject
Has Abstractpub_date
1992-06-01 00:00:00pages
5188-91issue
11eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::The Abeta peptide of Alzheimer disease is derived from the proteolytic processing of the amyloid precursor proteins (APP), which are considered type I transmembrane glycoproteins. Recently, however, soluble forms of full-length APP were also detected in several systems including chromaffin granules. In this report we ...
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.93.15.8046
更新日期:1996-07-23 00:00:00
abstract::The free radicals nitric oxide and superoxide anion react to form peroxynitrite (ONOO-), a highly toxic oxidant species. In vivo formation of ONOO- has been demonstrated in shock and inflammation. Herein we provide evidence that cytotoxicity in cells exposed to ONOO- is mediated by DNA strand breakage and the subseque...
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.93.5.1753
更新日期:1996-03-05 00:00:00
abstract::Expressions are developed for weak single pair emission probability and strong emission average number of pairs. The water transparency cutoff is closely realized, showing that the fundamental time scale is even shorter. ...
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.90.10.4505
更新日期:1993-05-15 00:00:00
abstract::Most, but not all, aged rats exhibit a profound deficit in spatial memory when tested in a radial maze--a task known to depend on the integrity of the hippocampal formation. In this study, animals were divided into three groups based on their spatial memory capacity: young adult rats with good memory, aged rats with 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.83.9.3027
更新日期:1986-05-01 00:00:00
abstract::The tumor promoter phorbol 12-myristate 13-acetate (PMA) induces characteristic reversible changes of cell shape in certain fibroblastic lines: motile lamellas are transformed into noncontractile narrow processes; simultaneously, the actin microfilament network of lamellas is locally disorganized. This reaction to PMA...
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.87.5.1884
更新日期:1990-03-01 00:00:00
abstract::HIV type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry into target cells. Here we show that the HIV-1 envelope gp120 (Env) activates multiple ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. Env from both CCR5-dependent JRFL (R5) an...
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.090521697
更新日期:2000-04-25 00:00:00
abstract::Utilizing [3H]phorbol dibutyrate [P(Bu)2], we have developed an assay for high-affinity phorbol ester receptors in intact rat embryo fibroblasts. At 37 degrees C, binding of [3H]P(Bu)2 reached a maximum within 10 min and was rapidly reversible. The tumor promoters 12-O-tetradecanoyl-phorbol 13-acetate, teleocidin B, a...
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.78.4.2315
更新日期:1981-04-01 00:00:00
abstract::Regulation of cardiac contraction by neurotransmitters and hormones is often correlated with regulation of the L-type Ca2(+)-channel current (ICa) through the opposite actions of two second messengers, cyclic AMP and cyclic GMP. While cyclic AMP stimulation of ICa is mediated by the activation of cyclic AMP-dependent ...
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.88.4.1197
更新日期:1991-02-15 00:00:00
abstract::Lipid rafts are important signaling platforms in T cells. Little is known about their properties in human CD8(+) T cells. We studied polarization of lipid rafts by digital immunofluorescence microscopy in primary human T cells, using beads coated with anti-CD3 and anti-CD28 mAbs (CD3/28 beads). Unlike CD4(+) T cells, ...
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.232058599
更新日期:2002-11-12 00:00:00
abstract::Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) has been implicated in Parkinson's disease (PD) and is present in neurofibrillary tangles or Lewy bodies. However, the molecular basis for UCH-L1s involvement in proteinacious fibril formation is still elusive, especially in regard to the pathogenicity of the I93M muta...
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.1002295107
更新日期:2010-04-13 00:00:00
abstract::Many and diverse modifications of the myosin subfragment 1 (S-1) increase (modulate) its ATPase activity, including interaction of this particle with actin; a recent addition to these modifications is the extensive lysine modification of S-1 that seems prerequisite to crystallizing it for structure analysis. In this 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.91.18.8665
更新日期:1994-08-30 00:00:00
abstract::C.B-17 severe combined immunodeficient (scid) mice carry the scid mutation and are severely deficient in both T cell- and B cell-mediated immunity, apparently as a result of defective V(D)J joining of the immunoglobulin and T-cell receptor gene elements. In the present studies, we have defined the tissue, cellular, an...
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.88.4.1394
更新日期:1991-02-15 00:00:00
abstract::Maintenance of genomic stability is essential for normal organismal development and is vital to prevent diseases such as cancer. As genetic information is packaged into chromatin, it has become increasingly clear that the chromatin environment plays an important role in DNA damage response. However, how DNA repair is ...
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.1324036111
更新日期:2014-05-13 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::The development of anther and pollen is important for male reproduction, and this process is coordinately regulated by many external and internal cues. In this study, we systematically examined the male reproductive phenotypes of a series of brassinosteroid biosynthetic and signaling mutants and found that, besides th...
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.0912333107
更新日期:2010-03-30 00:00:00
abstract::Efforts to understand the dramatic declines in mortality over the past century have focused on life expectancy. However, understanding changes in disparity in age of death is important to understanding mechanisms of mortality improvement and devising policy to promote health equity. We derive a novel decomposition of ...
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.1601112113
更新日期:2016-07-26 00:00:00
abstract::Interferon regulatory factor (IRF) 4 is a member of the IRF family of transcription factors and plays critical roles in the development of CD4(+) T cells into Th2 and Th17 cells. Using the infection model of Nippostrongyrus brasiliensis, we have confirmed the critical roles of IRF-4 in Th2 development in vivo by using...
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.0803171105
更新日期:2008-10-14 00:00:00
abstract::Plants adapt to alterations in light conditions by controlling their gene expression profiles. Expression of light-inducible genes is transcriptionally induced by transcription factors such as HY5. However, few detailed analyses have been carried out on the control of transcription start sites (TSSs). Of the various w...
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.1804971115
更新日期:2018-07-24 00:00:00
abstract::Efforts are underway to construct several recoded genomes anticipated to exhibit multivirus resistance, enhanced nonstandard amino acid (nsAA) incorporation, and capability for synthetic biocontainment. Although our laboratory pioneered the first genomically recoded organism (Escherichia coli strain C321.∆A), its fitn...
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.1715530115
更新日期:2018-03-20 00:00:00
abstract::The primate gastrointestinal tract is home to trillions of bacteria, whose composition is associated with numerous metabolic, autoimmune, and infectious human diseases. Although there is increasing evidence that modern and Westernized societies are associated with dramatic loss of natural human gut microbiome diversit...
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.1521835113
更新日期:2016-09-13 00:00:00
abstract::There is significant variation in the reported magnitude and even the sign of [Formula: see text] shifts in thin polymer films with nominally the same chemistry, film thickness, and supporting substrate. The implicit assumption is that methods used to estimate [Formula: see text] in bulk materials are relevant for inf...
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.1722024115
更新日期:2018-05-29 00:00:00
abstract::Inflammation is a hallmark of many diseases, such as atherosclerosis, chronic obstructive pulmonary disease, arthritis, infectious diseases, and cancer. Although steroids and cyclooxygenase inhibitors are effective antiinflammatory therapeutical agents, they may cause serious side effects. Therefore, developing unique...
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.0914414107
更新日期:2010-05-25 00:00:00
abstract::Mature larvae of Sarcophaga argyrostoma fail to form puparia when kept in contact with water, but pupariate after having been subsequently exposed to dryness for 30 hr. They become increasingly more sensitive to injected ecdysone the longer the exposure to dry conditions. A second wet treatment halts the production of...
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.67.1.331
更新日期:1970-09-01 00:00:00
abstract::Cryogenic fluorescent light microscopy of flash-frozen cells stands out by artifact-free fixation and very little photobleaching of the fluorophores used. To attain the highest level of resolution, aberration-free immersion objectives with accurately matched immersion media are required, but both do not exist for imag...
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.1717282115
更新日期:2018-02-06 00:00:00
abstract::The coordinated redistribution of sugars from mature "source" leaves to developing "sink" leaves requires tight regulation of sugar transport between cells via plasmodesmata (PD). Although fundamental to plant physiology, the mechanisms that control PD transport and thereby support development of new leaves have remai...
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.1919196117
更新日期:2020-03-03 00:00:00
abstract::We study the dynamic network of e-mail traffic and find that it develops self-organized coherent structures similar to those appearing in many nonlinear dynamic systems. Such structures are uncovered by a general information theoretic approach to dynamic networks based on the analysis of synchronization among trios of...
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.0405728101
更新日期:2004-10-05 00:00:00
abstract::Tetrodotoxin was infused into the suprachiasmatic nuclei of unanesthetized and unrestrained rats continuously for 14 days. The internal timekeeping mechanism of the circadian pacemaker in the nuclei continued to oscillate unaffected by this treatment, although the toxin reversibly blocked function of both the input pa...
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.84.6.1694
更新日期:1987-03-01 00:00:00
abstract::We show that a drop of liquid a few hundred microns in diameter placed under a solid, elastic, thin film (∼10 μm thick) causes it to bulge by tens of microns. The deformed shape is governed by equilibrium of tensions exerted by the various interfaces and the solid film, a form of Neumann's triangle. Unlike Young's equ...
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.1304587110
更新日期:2013-06-25 00:00:00
abstract::When an algorithm in dimension one is extended to dimension d, in nearly every case its computational cost is taken to the power d. This fundamental difficulty is the single greatest impediment to solving many important problems and has been dubbed the curse of dimensionality. For numerical analysis in dimension d, we...
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.112329799
更新日期:2002-08-06 00:00:00
abstract::Mixed synthetic oligonucleotides encoding sequences conserved among tyrosine-specific protein kinases were used to probe the genome of the budding yeast Saccharomyces cerevisiae. Two genes with homology to protein kinases were isolated and characterized by DNA sequence analysis. These genes, designated KIN1 and KIN2, ...
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.84.17.6035
更新日期:1987-09-01 00:00:00