Abstract:
:Vibrio cholerae O1 exists as two major serotypes, Inaba and Ogawa, which are associated with the O antigen of the lipopolysaccharide and are capable of unequal reciprocal interconversion. The 20-kilobase rfb regions encoding O-antigen biosynthesis in strains 569B (Inaba) and O17 (Ogawa) have been cloned in Escherichia coli K-12 and the nucleotide sequences have been determined. Besides several base substitutions and a small deletion in the 569B sequence relative to O17, there is a single nucleotide change resulting in a TGA stop codon within the gene for the 32-kDa RfbT protein. We have demonstrated that rfbT is responsible for serotype conversion (Inaba to Ogawa). The construction of a specific rfbT mutation in the Ogawa strain O17, and the ability of the gene from O17 to complement Inaba strains to Ogawa, confirmed rfbT as the gene required for the Ogawa serotype. By Southern hybridization and sequencing of PCR products of a number of strains, we have shown that the changes observed in one Inaba strain (569B) are not conserved in other Inaba strains. This may explain why some Inaba strains are able to convert to Ogawa whereas others are not. The protein encoded by rfbT has been identified and expressed in E. coli K-12 using a phage T7 expression system. Amino-terminal analysis of partially purified protein has identified the translational start of the protein. Primer extension studies have enabled the 5' end of the mRNA to be defined. It exists as a separate transcript from the rest of the rfb region, and the distinctive G + C content of rfbT suggests that it has been acquired from a non-Vibrio source.
journal_name
Proc Natl Acad Sci U S Aauthors
Stroeher UH,Karageorgos LE,Morona R,Manning PAdoi
10.1073/pnas.89.7.2566keywords:
subject
Has Abstractpub_date
1992-04-01 00:00:00pages
2566-70issue
7eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::RelB is an NF-κB family transcription factor activated in the noncanonical pathway downstream of NF-κB-inducing kinase (NIK) and TNF receptor family members including lymphotoxin-β receptor (LTβR) and CD40. Early analysis suggested that RelB is required for classical dendritic cell (cDC) development based on a severe ...
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.1619863114
更新日期:2017-04-11 00:00:00
abstract::A mathematical method is developed which enables us to treat exactly the process of coincidental evolution under mutation, unequal intrachromosomal crossing-over as well as ordinary crossing-over between homologous chromosomes in a finite population of the effective size N. It makes use of finite difference equations ...
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.76.8.4001
更新日期:1979-08-01 00:00:00
abstract::We investigated patterns of genetic diversity of Plasmodium falciparum associated with its two main African vectors: Anopheles gambiae and Anopheles funestus. We dissected 10,296 wild-caught mosquitoes from three tropical sites, two in Cameroon (Simbock and Tibati, separated by 320 km) and one in Kenya (Rota, >2,000 k...
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.0702715104
更新日期:2007-05-08 00:00:00
abstract::1-Aminocyclopropane-1-carboxylate (ACC) synthase (EC 4.4.1.14), extracted from tomato pericarp tissue, was purified 6500-fold by conventional and high-performance liquid chromatography. Two-dimensional gel electrophoresis of this preparation indicated that ACC synthase activity was associated with a protein band at 50...
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.83.20.7755
更新日期:1986-10-01 00:00:00
abstract::The mechanisms involved in the uptake of uni- and multi-lamellar lipid vesicles by BALB/c mouse 3T3 cells have been investigated. Vesicles are incorporated into cells both by endocytosis and by a nonendocytotic mechanism which we propose involves fusion of vesicles with the plasma membrane. The nonendocytotic pathway ...
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.73.5.1603
更新日期:1976-05-01 00:00:00
abstract::Glyco-immune checkpoint receptors, molecules that inhibit immune cell activity following binding to glycosylated cell-surface antigens, are emerging as attractive targets for cancer immunotherapy. Defining biologically relevant ligands that bind and activate such receptors, however, has historically been a significant...
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.2015024118
更新日期:2021-02-02 00:00:00
abstract::Fibrodysplasia ossificans progressiva (FOP) patients carry a missense mutation in ACVR1 [617G > A (R206H)] that leads to hyperactivation of BMP-SMAD signaling. Contrary to a previous study, here we show that FOP fibroblasts showed an increased efficiency of induced pluripotent stem cell (iPSC) generation. This positiv...
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.1603668113
更新日期:2016-11-15 00:00:00
abstract::A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extincti...
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.1001706107
更新日期:2010-04-13 00:00:00
abstract::Valproic acid (VPA) is an anticonvulsant drug that is also used to treat migraines and bipolar disorder. Its proposed biological targets include human voltage-gated sodium channels, among other membrane proteins. We used the prokaryotic NavMs sodium channel, which has been shown to be a good exemplar for drug binding ...
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.1909696116
更新日期:2019-12-10 00:00:00
abstract::Physical activity increases energy metabolism in exercising muscle. Whether acute exercise elicits metabolic changes in nonexercising muscles remains unclear. We show that one of the few genes that is more highly induced in nonexercising muscle than in exercising human muscle during acute exercise encodes angiopoietin...
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.1400889111
更新日期:2014-03-18 00:00:00
abstract::Tobacco mosaic virus (TMV) RNA was encapsulated in large, unilamellar phospholipid vesicles (liposomes), and the encapsulated TMV RNA was shown to be infectious when incubated with tobacco protoplasts under appropriate conditions. Maximal virus production in protoplasts was observed after their incubation with TMV RNA...
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.79.6.1859
更新日期:1982-03-01 00:00:00
abstract::In the vertebrate central nervous system, the retina has been a useful model for studies of cell fate determination. Recent results from studies conducted in vitro and in vivo suggest a model of retinal development in which both the progenitor cells and the environment change over time. The model is based upon the not...
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.93.2.589
更新日期:1996-01-23 00:00:00
abstract::The G12 subfamily of heterotrimeric G proteins, comprised of the alpha-subunits Galpha12 and Galpha13, has been implicated as a signaling component in cellular processes ranging from cytoskeletal changes to cell growth and oncogenesis. In an attempt to elucidate specific roles of this subfamily in cell regulation, 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.021350998
更新日期:2001-01-16 00:00:00
abstract::Brown-rot fungi such as Postia placenta are common inhabitants of forest ecosystems and are also largely responsible for the destructive decay of wooden structures. Rapid depolymerization of cellulose is a distinguishing feature of brown-rot, but the biochemical mechanisms and underlying genetics are poorly understood...
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.0809575106
更新日期:2009-02-10 00:00:00
abstract::The FMS gene encodes the functional cell surface receptor for colony-stimulating factor 1, the macrophage- and monocyte-specific growth factor. Codons 969 and 301 have been identified as potentially involved in promoting the transforming activity of FMS. Mutations at codon 301 are believed to lead to neoplastic transf...
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.87.4.1377
更新日期:1990-02-01 00:00:00
abstract::Children whose parents divorce tend to have worse educational outcomes than children whose parents stay married. However, not all children respond identically to their parents divorcing. We focus on how the impact of parental divorce on children's education varies by how likely or unlikely divorce was for those parent...
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.1813049116
更新日期:2019-04-09 00:00:00
abstract::Because the insolubility of the scrapie prion protein (PrP(Sc)) has frustrated structural studies by x-ray crystallography or NMR spectroscopy, we used electron crystallography to characterize the structure of two infectious variants of the prion protein. Isomorphous two-dimensional crystals of the N-terminally trunca...
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.052703499
更新日期:2002-03-19 00:00:00
abstract::We report the development of a practical ultrafast allelic profiling assay for the analysis of short tandem repeats (STRs) by using a highly optimized microfluidic electrophoresis device. We have achieved baseline-resolved electrophoretic separations of single-locus STR samples in 30 sec. Analyses of PCR samples conta...
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.94.19.10273
更新日期:1997-09-16 00:00:00
abstract::Efficiently regenerated single colonies from mixed multiply auxotrophic Bacillus subtilis protoplasts, fused with polyethylene glycol, reveal colonies carrying each of the parent types (biparentals) and recombinant colonies. The latter appear in high yields (up to 1% of certain recombinant classes); the yield of bipar...
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.77.6.3553
更新日期:1980-06-01 00:00:00
abstract::The double-stranded RNA (dsRNA)-dependent protein kinase (PKR) is induced as part of the IFN response in mammals and acts to shut down protein synthesis by the phosphorylation of eukaryotic initiation factor 2alpha (eIF2alpha). In fish, a PKR-like kinase activity has been detected, but the enzyme responsible has elude...
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.0408714102
更新日期:2005-02-01 00:00:00
abstract::Murine and human cDNAs, related to but distinct from c-raf-1, have been isolated and designated mA-raf and hA-raf, respectively. The mA-raf and hA-raf cDNAs detect the same murine and human fragments in Southern blots of restriction enzyme-cleaved murine and human cellular DNA. The murine restriction enzyme fragments ...
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.83.11.3934
更新日期:1986-06-01 00:00:00
abstract::The surface density of the triggering receptors responsible for the natural killer (NK)-mediated cytotoxicity is crucial for the ability of NK cells to kill susceptible target cells. In this study, we show that transforming growth factor beta1 (TGFbeta1) down-regulates the surface expression of NKp30 and in part of NK...
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.0730640100
更新日期:2003-04-01 00:00:00
abstract::Prey shifts in carnivorous predators are events that can initiate the accelerated generation of new biodiversity. However, it is seldom possible to reconstruct how the change in prey preference occurred. Here we describe an evolutionary "smoking gun" that illuminates the transition from worm hunting to fish hunting am...
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.1424435112
更新日期:2015-04-21 00:00:00
abstract::The activation of additional promoter sites by production of an alternative sigma subunit for RNA polymerase is a common strategy for the coordinate regulation of gene expression. Many alternative sigma factors control genes for specialized, and often narrowly distributed, functions. For example, most of the alternati...
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.89.11.5123
更新日期:1992-06-01 00:00:00
abstract::We modeled the behavior of recessive mutations with deleterious effects to either the sporophyte or the gametophyte, or both, in polysomic tetraploid populations by allowing for varying levels of double reduction, mutation, and self-fertilization. Double reduction causes a decrease of the equilibrium frequencies of de...
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.100101097
更新日期:2000-06-06 00:00:00
abstract::The inability to perceive and coordinate both internal and external signals that function to regulate cellular growth and proliferation is a hallmark of oncogenic transformation. To examine the effects of the v-mos oncogene on distinct signal transduction pathways, the 6m2 cell line was used, in which expression of 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.86.2.597
更新日期:1989-01-01 00:00:00
abstract::The lck gene encodes a membrane-associated protein tyrosine kinase (p56lck) that is believed to participate in lymphocyte-specific signal transduction pathways. To investigate the function of this molecule, transgenic mice were generated carrying the wild-type lck gene or a mutated lck gene encoding a constitutively 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.88.9.3977
更新日期:1991-05-01 00:00:00
abstract::Immobilizing a protein, that is fully compatible with the patient, on the surface of a biomedical device should make it possible to avoid adverse responses such as inflammation, rejection, or excessive fibrosis. A surface that strongly binds and does not denature the compatible protein is required. Hydrophilic surface...
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.1103277108
更新日期:2011-08-30 00:00:00
abstract::Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure 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.1523683113
更新日期:2016-01-19 00:00:00
abstract::Agents that act as anion channel blockers (ACBs) and do not permeate cells appear to inhibit exocytosis in platelets, parathyroid cells, and neutrophils. Based in large part on these observations, anion influx through plasma membrane channels has been considered a factor controlling cellular secretion, but there have ...
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.86.15.5839
更新日期:1989-08-01 00:00:00