Abstract:
:It is not yet clear how bacterial outer membrane proteins reach their correct destination after they are secreted across the cytoplasmic membrane. We show here that porin OmpF is secreted into the medium as a water-soluble monomeric protein by spheroplasts of Escherichia coli. Furthermore, this monomeric porin is taken up by cell envelope preparations or purified lipopolysaccharides in the presence of 0.03% Triton X-100 and is converted correctly into the mature trimeric conformation. These results appear to reproduce a part of the physiological export and targeting steps of this protein.
journal_name
Proc Natl Acad Sci U S Aauthors
Sen K,Nikaido Hdoi
10.1073/pnas.87.2.743subject
Has Abstractpub_date
1990-01-01 00:00:00pages
743-7issue
2eissn
0027-8424issn
1091-6490journal_volume
87pub_type
杂志文章abstract::Soret-excited resonance Raman spectroscopy yields direct information regarding the iron-carbon bonding interactions in the cyanomet and carbonmonoxy complexes of hemoglobin III from Chironomus thummi thummi (CTT III) in solution. By isotope exchange in cyanide (13CN-, C15N-, and 13C15N-) and carbon monoxide (13CO, C18...
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.81.16.5106
更新日期:1984-08-01 00:00:00
abstract::p21Sdi1 (also known as Cip1 and Waf1), an inhibitor of DNA synthesis cloned from senescent human fibroblasts, is an inhibitor of G1 cyclin-dependent kinases (Cdks) in vitro and is transcriptionally regulated by wild-type p53. In addition, p21Sdi1 has been found to inhibit DNA replication by direct interaction with pro...
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.92.10.4352
更新日期:1995-05-09 00:00:00
abstract::During meiosis, homologous chromosomes recombine and become closely apposed along their lengths within the synaptonemal complex (SC). In part because Spo11 is required both to make the double-strand breaks (DSBs) that initiate recombination and to promote normal SC formation in many organisms, it is clear that these 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.0400843101
更新日期:2004-03-30 00:00:00
abstract::Understanding the heritability of neural systems linked to psychopathology is not sufficient to implicate them as intergenerational neural mediators. By closely examining how individual differences in neural phenotypes and psychopathology cosegregate as they fall through the family tree, we can identify the brain syst...
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.1508593112
更新日期:2015-07-21 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::Although introduced hemosporidian (malaria) parasites (Apicomplexa: Haemosporida) have hastened the extinction of endemic bird species in the Hawaiian Islands and perhaps elsewhere, little is known about the temporal dynamics of endemic malaria parasite populations. Haemosporidian parasites do not leave informative fo...
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.1702512114
更新日期:2017-06-20 00:00:00
abstract::A protein that specifically binds leukemia inhibitory factor (LIF) has been isolated from normal mouse serum by using four successive fractionation steps: chromatography on a LIF affinity matrix, anion-exchange chromatography, size-exclusion chromatography, and preparative native gel electrophoresis. The purified LIF-...
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.89.18.8616
更新日期:1992-09-15 00:00:00
abstract::Antibodies to the insulin receptor were prepared in BALB/c mice by immunization with IM-9 human lymphocytes, a cell type that has a large number of plasma membrane insulin receptors. The spleens of these mice were then removed, and their lymphocytes were fused to a mouse myeloma cell line, FO cells. After screening ov...
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.79.23.7312
更新日期:1982-12-01 00:00:00
abstract::The origin-binding protein (OBP) from herpes simplex virus 1 is a member of the SF2 helicase superfamily and is required for the initiation of DNA synthesis from a viral origin of DNA replication (oriS). The high-affinity binding sites for OBP in oriS, boxes I and II, are separated by an A+T-rich spacer. We used the 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.91.11.4629
更新日期:1994-05-24 00:00:00
abstract::Steroidogenic factor-1 (SF-1) and liver receptor homologue-1 (LRH-1) belong to the fushi tarazu factor 1 subfamily of nuclear receptors. SF-1 is an essential factor for sex determination during development and regulates adrenal and gonadal steroidogenesis in the adult, whereas LRH-1 is a critical factor for developmen...
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.0409482102
更新日期:2005-05-24 00:00:00
abstract::Supported metal catalysts are extensively used in industrial and environmental applications. To improve their performance, it is crucial to identify the most active sites. This identification is, however, made challenging by the presence of a large number of potential surface structures that complicate such an assignm...
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.2002342117
更新日期:2020-06-30 00:00:00
abstract::Recent years have witnessed an increased public outcry in certain quarters about a perceived lack of attention given to successful members of disadvantaged groups relative to equally meritorious members of advantaged groups, exemplified by social media campaigns centered around hashtags, such as #OscarsSoWhite and #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.1818545116
更新日期:2019-01-29 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::Switch from non-syncytium-inducing (NSI) to syncytium-inducing (SI) HIV type 1 (HIV-1) is associated with accelerated CD4(+) T cell depletion, which might partially be explained by higher virulence of SI variants compared with NSI variants. Because NSI and SI variants use different coreceptors for entry of target cell...
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.97.3.1269
更新日期:2000-02-01 00:00:00
abstract::Chondrules may have played a critical role in the earliest stages of planet formation by mediating the accumulation of dust into planetesimals. However, the origin of chondrules and their significance for planetesimal accretion remain enigmatic. Here, we show that chondrules and matrix in the carbonaceous chondrite Al...
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.1524980113
更新日期:2016-03-15 00:00:00
abstract::The Pleistocene global dispersal of modern humans required the transit of arid and semiarid regions where the distribution of potable water provided a primary constraint on dispersal pathways. Here, we provide a spatially explicit continental-scale assessment of the opportunities for Pleistocene human occupation of Au...
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.1608470113
更新日期:2016-10-11 00:00:00
abstract::Surgical removal of one or both atrial appendages was employed in rats to reduce the intrinsic stores of atriopeptin (AP). In conscious rats (with intact baroreceptor reflexes), bilateral or unilateral atrial appendectomy suppressed the diuresis and natriuresis produced by acute volume expansion. Surprisingly, volume ...
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.85.9.3155
更新日期:1988-05-01 00:00:00
abstract::Maternal microchimerism (MMc) has been associated with development of allospecific transplant tolerance, antitumor immunity, and cross-generational reproductive fitness, but its mode of action is unknown. We found in a murine model that MMc caused exposure to the noninherited maternal antigens in all offspring, but 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.1618364114
更新日期:2017-01-31 00:00:00
abstract::A method is proposed for rapidly, quantitatively comparing protein structures of arbitrary sizes, based on the differential geometric representation. The method is applied to a group of 22 protein x-ray structures, and the resulting network of closest relationships is delineated. Several well-known fold types are auto...
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.85.3.777
更新日期:1988-02-01 00:00:00
abstract::Lipoproteins are emulsion particles that consist of lipids and apolipoproteins. Their natural function is to transport lipids and/or cholesterol to different tissues. We have taken advantage of the hydrophobic interior of these natural emulsions to solubilize DNA. Negatively charged DNA was first complexed with cation...
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.94.26.14547
更新日期:1997-12-23 00:00:00
abstract::A polypeptide was isolated from acid extracts of porcine hypothalami on the basis of its high ability to stimulate the release of corticotropin from superfused rat pituitary cells. After an initial separation by gel filtration on Sephadex G-25, further purification was carried out by reversed-phase HPLC. The isolated ...
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.82.24.8762
更新日期:1985-12-01 00:00:00
abstract::The study of photoinitiated electron transfer in donor-bridge-acceptor molecules has helped elucidate the distance dependence of electron transfer rates and behavior of various electron transfer mechanisms. In all reported cases, the energies of the bridge electronic states involved in the electron transfer change dra...
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.0408940102
更新日期:2005-03-08 00:00:00
abstract::We have isolated cold-sensitive mutations in two genes of the yeast Saccharomyces cerevisiae, BIN2 and BIN3, that cause aberrant chromosome segregation in vivo. BIN2 and BIN3 encode essential proteins that are similar to each other and to TCP-1. TCP-1 and TCP-1-like proteins are components of the eukaryotic cytoplasmi...
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.91.19.9111
更新日期:1994-09-13 00:00:00
abstract::Genetic manipulation of the alpha(2A)-adrenergic receptor (alpha(2A)-AR) in mice has revealed the role of this subtype in numerous responses, including agonist-induced hypotension and sedation. Unexpectedly, alpha(2)-agonist treatment of mice heterozygous for the alpha(2A)-AR (alpha(2A)-AR(+/-)) lowers blood pressure ...
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.122368499
更新日期:2002-09-17 00:00:00
abstract::We have used methods that have allowed simultaneous fluorescent staining of intracellular actin together with either myosin, filamin, or tubulin in normal rat kidney fibroblasts in monolayer culture. In the main portions of the cell body, the actin, myosin, and filamin are all present in two structures: in one, the 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.74.9.3883
更新日期:1977-09-01 00:00:00
abstract::The four core histones (H2A, H2B, H3, and H4) and DNA were assembled into nucleosome-like particles at physiological ionic strengths either by an extract of chromatin rich in nicking-closing activity or by the purified nicking-closing enzyme itself. When histone-DNA complexes were assembled in vitro from relaxed circu...
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.76.8.3779
更新日期:1979-08-01 00:00:00
abstract::Using the Luria-Delbrück fluctuation analysis, we have examined the lung tumor-forming ability of a series of parallel clones derived from the KHT tumor, grown to small defined sizes. From these studies, we conclude that metastatic variants arise spontaneously in the clonal lines during their growth, at an apparent ra...
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.79.18.5547
更新日期:1982-09-01 00:00:00
abstract::Knowledge of normal human cardiac excitation stems from isolated heart or intraoperative mapping studies under nonphysiological conditions. Here, we use a noninvasive imaging modality (electrocardiographic imaging) to study normal activation and repolarization in intact unanesthetized healthy adults under complete phy...
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.0601533103
更新日期:2006-04-18 00:00:00
abstract::DNA in the macronuclei of Oxytricha fallax, as in other hypotrichous ciliate protozoa, exists as small, achromosomal molecules rather than in chromosomes. We report studies on O. fallax DNA using physicochemical procedures and nucleic acid hybridization. Macronuclear DNA molecules range in size from 22 kilobase pairs ...
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.75.10.4992
更新日期:1978-10-01 00:00:00
abstract::Viruses are obligatory intracellular parasites that suffer strong evolutionary pressure from the host immune system. Rapidly evolving viral genomes can adapt to this pressure by acquiring genes that counteract host defense mechanisms. For example, many vertebrate DNA viruses have hijacked cellular genes encoding cytok...
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.1516122113
更新日期:2016-01-19 00:00:00