Abstract:
:Diphtheria toxin ( DTx ) is an extremely potent inhibitor of protein synthesis. It is secreted as a linear polypeptide, which is cleaved to produce disulfide-linked A and B fragments. Fragment A, the inhibitor of protein synthesis, requires fragment B, the recognition subunit, for entry into intact cells. Fragment B has been proposed to form a transmembrane channel through which A gains access to the cytosol. If it were demonstrated that the B subunit had an exclusive association with membrane lipid acyl chains, this might indicate that A is secluded in a proteinaceous B channel. However, our results from intramembranous photolabeling studies show that both subunits of DTx enter the hydrocarbon domain of the bilayer. Toxin cleavage is not required for penetration. Decreasing pH leads to increased binding and hence indirectly to increased penetration. Parallel permeability studies indicate that cleaved DTx does indeed form pores (24 A in diameter) and they are larger than those previously reported (5 A) with native toxin. The data suggest that these are dimeric structures. Cleaved DTx is much more effective than intact DTx at pore formation. Thus, we conclude that, while pore formation is a feature of toxin-membrane interaction, the pore structure does not protect A from contact with lipid side chains and may in fact consist of both the A and B domains in a dimeric configuration, (AB)2.
journal_name
Proc Natl Acad Sci U S Aauthors
Zalman LS,Wisnieski BJdoi
10.1073/pnas.81.11.3341subject
Has Abstractpub_date
1984-06-01 00:00:00pages
3341-5issue
11eissn
0027-8424issn
1091-6490journal_volume
81pub_type
杂志文章abstract::The location of phosphate residues involved in specific centers for binding of metal ions in M1 RNA, the catalytic RNA subunit of RNase P from Escherichia coli, was determined by analysis of induction of cleavage of RNA by metal ions. At pH 9.5, Mg2+ catalyzes cleavage of M1 RNA at five principal sites. Under certain ...
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.88.20.9193
更新日期:1991-10-15 00:00:00
abstract::Gene duplication is an important mechanism in the evolution of protein interaction networks. Duplications are followed by the gain and loss of interactions, rewiring the network at some unknown rate. Because rewiring is likely to change the distribution of network motifs within the duplicated interaction set, it shoul...
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.0707293105
更新日期:2008-01-22 00:00:00
abstract::The subventricular zone remains mitotically active throughout life in rodents. Studies with tritiated thymidine, which is incorporated into the DNA of mitotic cells, have revealed that the rodent subventricular zone produces neuroblasts that migrate toward the olfactory bulb along the rostral migratory stream. A simil...
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.172403999
更新日期:2002-08-20 00:00:00
abstract::There is considerable evidence that links the activation of cellular genes to oncogenesis. We previously reported that structural rearrangements in the cellular oncogene c-erbB correlate with the development of erythroblastosis induced by avian leukosis virus (ALV). c-erbB recently has been shown to be related to the ...
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.82.8.2287
更新日期:1985-04-01 00:00:00
abstract::cDNA clones for the (S)-tetrahydroberberine (H4Ber) oxidase of cultured berberine-producing Coptis japonica cells were isolated by screening a C. japonica cDNA library with synthetic nucleotides that can encode the NH2-terminal sequence of this enzyme. Analyses of the nucleotide sequences of the cloned cDNA inserts 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.86.2.534
更新日期:1989-01-01 00:00:00
abstract::Competing interpretations of human origins and evolution have recently proliferated despite the accelerated pace of fossil discovery. These controversies parallel those involving other vertebrate families and result from the difficulty of studying evolution among closely related species. Recent advances in development...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.0307678101
更新日期:2004-03-02 00:00:00
abstract::Antigen.antibody complexes (Ag.Ab) prepared from (125)I-labeled bovine serum albumin and guinea pig anti-albumin were incubated at 37 degrees C for 30 min with normal human serum diluted optimally for binding (1:16) and then with autologous erythrocytes (RBC). After washing, RBC-bearing antigen.antibody.complement com...
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.79.16.5047
更新日期:1982-08-01 00:00:00
abstract::The crystal structures of Escherichia coli thymidylate kinase (TmpK) in complex with P1-(5'-adenosyl)-P5-(5'-thymidyl)pentaphosphate and P1-(5'-adenosyl)P5-[5'-(3'-azido-3'-deoxythymidine)] pentaphosphate have been solved to 2.0-A and 2.2-A resolution, respectively. The overall structure of the bacterial TmpK is very ...
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.95.24.14045
更新日期:1998-11-24 00:00:00
abstract::The structural features that determine tRNA(Ala) acceptor identity have been studied with amber-suppressor tRNAs in Escherichia coli cells. Previous work established that a wobble pair composed of guanosine at position 3 and uridine at position 70 (G3-U70) in the acceptor helix of tRNA(Ala) is a determinant of the mol...
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.88.20.9272
更新日期:1991-10-15 00:00:00
abstract::We performed a genome-wide analysis of gene expression in primary human CD15(+) myeloid progenitor cells. By using the serial analysis of gene expression (SAGE) technique, we obtained quantitative information for the expression of 37,519 unique SAGE-tag sequences. Of these unique tags, (i) 25% were detected at high 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.051013798
更新日期:2001-03-13 00:00:00
abstract::High-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous mater...
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.1615926113
更新日期:2016-11-15 00:00:00
abstract::Humans reason about the mental states of others; this capacity is called Theory of Mind (ToM). In typically developing adults, ToM is supported by a consistent group of brain regions: the bilateral temporoparietal junction (TPJ), medial prefrontal cortex (MPFC), precuneus (PC), and anterior temporal sulci (aSTS). How ...
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.0900010106
更新日期:2009-07-07 00:00:00
abstract::The chemotaxis network in Escherichia coli is remarkable for its sensitivity to small relative changes in the concentrations of multiple chemical signals. We present a model for signal integration by mixed clusters of interacting two-state chemoreceptors. Our model results compare favorably to the results obtained by ...
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.0507438103
更新日期:2006-02-07 00:00:00
abstract::The recent characterization of the prokaryotic Cys(2)His(2) zinc-finger domain, identified in Ros protein from Agrobacterium tumefaciens, has demonstrated that, although possessing a similar zinc coordination sphere, this domain is structurally very different from its eukaryotic counterpart. A search in the databases ...
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.0810003106
更新日期:2009-04-28 00:00:00
abstract::Extracellular vesicles (EVs) secreted by cells present an attractive strategy for developing new therapies, but progress in the field is limited by several issues: The quality of the EVs varies with the type and physiological status of the producer cells; protocols used to isolate the EVs are difficult to scale up; 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.1522297113
更新日期:2016-01-05 00:00:00
abstract::Five recombinant DNA plasmids have been constructed that contain structural gene sequences for rat tyrosine hydroxylase [TyrOHase; tyrosine 3-monooxygenase; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2]. Rat pheochromocytoma PC 12 cell line, which contains relatively high level...
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.79.12.3881
更新日期:1982-06-01 00:00:00
abstract::Myocytes in the atria contain a prohormone that gives rise to atrial natriuretic peptides (ANP), which have intrinsic hemodynamic regulatory activity. Little is known about mechanisms regulating ANP release. In rats with indwelling catheters, acute blood volume expansion with 5% (wt/vol) dextrose increases the amount ...
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.84.2.541
更新日期:1987-01-01 00:00:00
abstract::Immunoglobulin- or multiple myeloma-associated amyloidosis has been distinguished by the tissue deposition of Congophilic, fibrillar protein consisting of light chains or light-chain fragments (AL amyloidosis). We now report the isolation and characterization of another form of immunoglobulin-associated amyloid obtain...
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.87.17.6542
更新日期:1990-09-01 00:00:00
abstract::In an earlier report, evidence was presented that the down-regulation of beta-actin mRNA during myogenesis was controlled by a region 3' to the promoter of the gene. In this paper we report the location of this regulatory sequence, determined by deletion analysis and the use of chimeric genes, transfected stably into ...
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.85.5.1389
更新日期:1988-03-01 00:00:00
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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.73.1.24
更新日期:1976-01-01 00:00:00
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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.1900194116
更新日期:2019-06-25 00:00:00
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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.1503533112
更新日期:2015-04-14 00:00:00
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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.1316235110
更新日期:2013-10-29 00:00:00
abstract::Nerve growth factor has been quantified by both bioassay and radial immunodiffusion in mouse saliva elicited by several secretagogues. The concentrations by bioassay of nerve growth factor in both epinephrine- and norepinephrine-induced saliva (3400 and 900 mug/ml, respectively) are higher than reported in any other 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.73.11.4210
更新日期:1976-11-01 00:00:00
abstract::The chromosomal locations of cellular sequences flanking integrated papillomavirus DNA in four cervical carcinoma cell lines and a primary cervical carcinoma have been determined. The two human papillomavirus (HPV) 16 flanking sequences derived from the tumor were localized to chromosome regions 20pter----20q13 and 3p...
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.84.4.1070
更新日期:1987-02-01 00:00:00
abstract::Telomerase is a special reverse transcriptase that extends one strand of the telomere repeat by using a template embedded in an RNA subunit. Like other polymerases, telomerase is believed to use a pair of divalent metal ions (coordinated by a triad of aspartic acid residues) for catalyzing nucleotide addition. Here 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.0502252102
更新日期:2005-07-12 00:00:00
abstract::Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation 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.1607745113
更新日期:2016-07-26 00:00:00
abstract::Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder and is strongly associated with obesity and type 2 diabetes. Currently, there is no approved pharmacological treatment for this disease, but improvement of insulin resistance using peroxisome proliferator-activated receptor-γ (PPARγ) ag...
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.1525093113
更新日期:2016-02-23 00:00:00
abstract::A double-stranded (ds) DNA which may be a replication intermediate was isolated from bean (Phaseolus vulgaris L. "Top Crop") leaves systemically infected with bean golden mosaic virus, a whitefly-transmitted plant virus with a genome of circular single-stranded (ss) DNA. The isolation method used phenol/chloroform ext...
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.78.7.4102
更新日期:1981-07-01 00:00:00
abstract::We have totally synthesized a gene that codes for rat hepatic cytochrome b5. The 5' flanking region was designed for efficient expression of this gene in Escherichia coli by incorporating an optimum ribosome binding site and spacer region. Both a soluble form, analogous to the protease-treated microsomal protein, as 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.83.24.9443
更新日期:1986-12-01 00:00:00