Abstract:
:Perfusion of rat hearts with Krebs--Henseleit medium containing 10 mM L-leucine methyl ester leads to swelling of lysosomes and loss of lysosomal integrity within 30-60 min. No morphological changes can be detected in the nuclei, mitochondria, sarcoplasmic reticulum, or Golgi complex as a result of the treatment with leucine methyl ester, and the hearts continue to beat normally during the treatment period. Homogenates of rat hearts perfused with the methyl ester exhibit a decrease in the sedimentability of cathepsin D activity compared to controls, thus providing additional evidence for a loss of lysosomal integrity. Swelling and disruption of the lysosomes presumably occurs because of the extensive accumulation of leucine within the organelles resulting from the intralysosomal hydrolysis of the freely permeating methyl ester. The lysosomal dysfunction that occurs with exposure to leucine methyl ester produces a 30% decrease in cardiac protein degradation. These results provide an estimate of the contribution of lysosomes to total protein degradation in the rat heart, and they also suggest that the enzymes released as a result of lysosomal disruption are relatively inactive in hydrolyzing cellular constituents under the perfusion conditions used here. The use of amino acid methyl esters to produce rapid, specific loss of lysosomal integrity in situ provides an approach to the study of lysosomal function in intact cells.
journal_name
Proc Natl Acad Sci U S Aauthors
Reeves JP,Decker RS,Crie JS,Wildenthal Kdoi
10.1073/pnas.78.7.4426subject
Has Abstractpub_date
1981-07-01 00:00:00pages
4426-9issue
7eissn
0027-8424issn
1091-6490journal_volume
78pub_type
杂志文章abstract::To investigate the evolution of the mammalian sex chromosomes, we have compared the gene content of the X chromosomes in the mammalian groups most distantly related to man (marsupials and monotremes). Previous work established that genes on the long arm of the human X chromosome are conserved on the X chromosomes in 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.88.24.11256
更新日期:1991-12-15 00:00:00
abstract::A detailed experimental investigation of Fe1+y Te (y = 0.11, 0.12) using pulsed magnetic fields up to 60 T confirms remarkable magnetic shape-memory (MSM) effects. These effects result from magnetoelastic transformation processes in the low-temperature antiferromagnetic state of these materials. The observation of mod...
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.1905271116
更新日期:2019-08-20 00:00:00
abstract::Earlier studies have shown that the DNA of herpes simplex virus 1 consists of two covalently linked components, L and S, each flanked by inverted repeats. The two components can invert, and viral DNA extracted from infected cells or virions consists of equimolar concentrations of four populations differing solely in 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.80.9.2690
更新日期:1983-05-01 00:00:00
abstract::Temperature lability of ADP-glucose pyrophosphorylase (AGP; glucose-1-phosphate adenylyltransferase; ADP: alpha-D-glucose-1-phosphate adenylyltransferase, EC 2.7.7.27), a key starch biosynthetic enzyme, may play a significant role in the heat-induced loss in maize seed weight and yield. Here we report the isolation 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.95.22.13342
更新日期:1998-10-27 00:00:00
abstract::Nicks within one strand of the bacteriophage T5 DNA molecule act as " weak points" for a novel kind mechanical breakage that can be utilized for "dissecting" the genome. The products from sheared T5(+) DNA include five unique double-stranded segments of the molecule and various combinations of adjacent segments. These...
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.71.5.2108
更新日期:1974-05-01 00:00:00
abstract::Pulmonary pathologies including adult respiratory distress syndrome are characterized by disruption of pulmonary integrity and edema compromising respiratory function. Sphingosine 1-phosphate (S1P) is a lipid mediator synthesized and/or stored in mast cells, platelets, and epithelial cells, with production up-regulate...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,收录出版
doi:10.1073/pnas.0501997102
更新日期:2005-06-28 00:00:00
abstract::Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, sy...
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.1516684112
更新日期:2015-12-22 00:00:00
abstract::Rapid electrical conduction in the His-Purkinje system tightly controls spatiotemporal activation of the ventricles. Although recent work has shed much light on the regulation of early specification and morphogenesis of the His-Purkinje system, less is known about how transcriptional regulation establishes impulse con...
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.1106911108
更新日期:2011-08-16 00:00:00
abstract::Natural abundance 13C spin-lattice (T1) relaxation time measurements are reported for unilamellar vesicles of 1,2-dipalmitoylphosphatidylcholine (1,2-dipalmitoyl-sn-glycero-3-phosphocholine), in the liquid crystalline phase, at magnetic field strengths of 1.40, 1.87, 2.35, 4.23, 7.05, 8.45, and 11.7 tesla (resonance 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.80.14.4325
更新日期:1983-07-01 00:00:00
abstract::The Eemian (last interglacial, 130-115 ka) was likely the warmest of all interglacials of the last 800 ka, with summer Arctic temperatures 3-5 °C above present. Here, we present improved Eemian climate records from central Greenland, reconstructed from the base of the Greenland Ice Sheet Project 2 (GISP2) ice core. Ou...
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.1524766113
更新日期:2016-08-30 00:00:00
abstract::A vaccinia virus host range mutant (hr mutant) deleted of 18 kilobase pairs at the left end of the genome has been employed to precisely map a viral gene required for multiplication in human cells. DNA fragments from the wild-type virus were inserted into the thymidine kinase gene of mutant virus by means of in vivo h...
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.83.15.5573
更新日期:1986-08-01 00:00:00
abstract::The mammalian innate immune system uses several sensors of double-stranded RNA (dsRNA) to develop the interferon response. Among these sensors are dsRNA-activated oligoadenylate synthetases (OAS), which produce signaling 2',5'-linked RNA molecules (2-5A) that activate regulated RNA decay in mammalian tissues. Differen...
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.1419409112
更新日期:2015-03-31 00:00:00
abstract::Bacteriophage 434 encodes a repressor that, like bacteriophage lambda repressor, both activates and represses transcription. As in the lambda chromosome, a region of the 434 chromosome, called the right operator, contains three repressor binding sites (OR1, OR2, and OR3) that mediate these effects on two adjacent prom...
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.83.24.9353
更新日期:1986-12-01 00:00:00
abstract::Ca(2+) is known to have important roles in sperm chemotaxis, although the relationship between intracellular Ca(2+) concentration ([Ca(2+)](i)) and modulation of the swimming and chemotactic behavior of spermatozoa has not been elucidated. Using a high-speed Ca(2+) imaging system, we examined the chemotactic behavior ...
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.0808580105
更新日期:2008-12-09 00:00:00
abstract::Mechanical injury to the adult mammalian spinal cord results in permanent loss of structural integrity at the lesion site and of the brain-controlled function distal to the lesion. Some of these consequences were permanently averted by altering the cellular constituents at the lesion site with x-irradiation delivered ...
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.93.20.11185
更新日期:1996-10-01 00:00:00
abstract::Deciphering the electron transfer reactivity characteristics of amyloid β-peptide copper complexes is an important task in connection with the role they are assumed to play in Alzheimer's disease. A systematic analysis of this question with the example of the amyloid β-peptide copper complex by means of its electroche...
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.1011315107
更新日期:2010-10-05 00:00:00
abstract::Recent cryoEM density maps of Abeta(42) fibrils obtained at low pH revealed two protofilaments winding around a hollow core raising the question if such tubular structures also exist at physiological pH. Based on the cryoEM measurements and on NMR data, we probe amyloid fibril organizations corresponding to the observ...
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.1004704107
更新日期:2010-08-10 00:00:00
abstract::High levels of inbreeding cause populations to become composed of homozygous, inbred lines. High levels of homozygosity limit the effectiveness of recombination, and therefore, retard the rate of decay of linkage (gametic phase) disequilibrium (LD) among mutations. Inbreeding and recombination interact to shape the ex...
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.0409804102
更新日期:2005-02-15 00:00:00
abstract::The complexed (ribosome-bearing) membrane fraction of Bacillus subtilis contains several proteins (CM-proteins) that are virtually absent from the ribosome-free fraction and hence might be components of the apparatus of protein secretion. We have determined, by trypsin digestion and by labeling with a nonpenetrating r...
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.80.11.3287
更新日期:1983-06-01 00:00:00
abstract::Enteritis caused by Clostridium difficile toxin (Tx) is a nosocomial disease of increasing clinical concern, but the local mediators of C. difficile TxA inflammation are unknown. The potent vasodilator calcitonin gene-related peptide mediates neurogenic inflammation via the calcitonin receptor-like receptor (CLR). Her...
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.1219733110
更新日期:2013-01-08 00:00:00
abstract::E2F is a heterodimeric transcription factor that regulates the expression of genes at the G1/S boundary and is composed of two related but distinct families of proteins, E2F and DP. E2F/DP heterodimers form complexes with the retinoblastoma (Rb) protein, the Rb-related proteins p107 and p130, and cyclins/cdks in a cel...
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.93.15.7594
更新日期:1996-07-23 00:00:00
abstract::The high-pressure behavior of amorphous selenium has been investigated with time-resolved diamond anvil cell synchrotron x-ray diffraction and computed microtomography techniques. A two-step dynamic crystallization process is observed in which the monoclinic phase crystallized from the amorphous selenium and gradually...
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.0806857105
更新日期:2008-09-09 00:00:00
abstract::Ethylenediaminetetraacetate and other divalent-cation-complexing agents greatly stimulate the cellular binding of DNA molecules to competent pneumococci, while the appearance of genetic transformants and nuclease-resistant DNA binding are completely inhibited. Based on this finding, we developed an experimental system...
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.71.4.1493
更新日期:1974-04-01 00:00:00
abstract::The complete amino acid sequence of Xenopus laevis nonmuscle myosin heavy chain B (MHC-B) has been deduced from overlapping cDNA clones isolated from an XTC cell library. RNA blots of various developmental stages, adult tissues, and XTC cells detect a single transcript of 7.5 kb which is expressed at similar levels 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.90.7.2856
更新日期:1993-04-01 00:00:00
abstract::RNA of a common strain of tobacco mosaic virus was sequentially reconstituted first with protein of the same strain and then with protein of a tomato strain. The reconstituted particles were treated with specific antibodies against the two strain particles and were examined electron microscopically to locate the regio...
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.74.5.1913
更新日期:1977-05-01 00:00:00
abstract::In eukaryotic cells the concentration of dNTP is highest in S phase and lowest in G1 phase and is controlled by ribonucleotide reductase (RNR). RNR activity is eliminated in all eukaryotes in G1 phase by a variety of mechanisms: transcriptional regulation, small inhibitory proteins, and protein degradation. After acti...
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.0610585104
更新日期:2007-01-23 00:00:00
abstract::Dolichol phosphate mannose (Dol-P-Man), formed upon transfer of Man from GDPMan to Dol-P, is a mannosyl donor in pathways leading to N-glycosylation, glycosyl phosphatidylinositol membrane anchoring, and O-mannosylation of protein. Dol-P-Man synthase is an essential protein in Saccharomyces cerevisiae. We have cloned ...
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.94.15.7873
更新日期:1997-07-22 00:00:00
abstract::The chemosmotic model provides a framework for visualizing energy-coupled reactions (vectorial reaction sequences, membrane-dependent gradient formation, and charge separation of reacting species) and a mechanism for energy coupling (indirect coupling between the driving and driven reaction sequences mediated by a mem...
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.78.4.2240
更新日期:1981-04-01 00:00:00
abstract::A paradigm of evolutionary biology is that adaptation and reproductive isolation are caused by a nearly infinite number of mutations of individually small effect. Here, we test this hypothesis by investigating the genetic basis of pollinator discrimination in two closely related species of monkeyflowers that differ in...
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.96.21.11910
更新日期:1999-10-12 00:00:00
abstract::Acute injury to the intestinal mucosa is a major dose-limiting complication of abdominal radiation therapy. We studied the role of the transcription factor NF-kappaB in protection against radiation-induced apoptosis in the intestinal epithelium in vivo. We use mice in which NF-kappaB signaling through IkappaB-kinase (...
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.0306734101
更新日期:2004-02-24 00:00:00