Abstract:
:Genetic evidence indicates that the PrlA (SecY) protein of Escherichia coli functions as a membrane integrated signal sequence receptor in protein "export"--i.e., in protein translocation across (or integration into) the plasma membrane. We have raised antibodies in rabbits against two synthetic peptides representing the hydrophilic N- or C-terminal region of PrlA. Using these antibodies as probes in cell fractionation experiments, we confirm that PrlA is an integral membrane protein of the plasma membrane of E. coli. Fab fragments prepared from each of the two antisera specifically inhibit protein export by interfering with the binding of preproteins to the plasma membrane. Inhibition of preprotein binding and export by Fab fragments was shown in a cell-free translocation system: precursors for LamB (an integral membrane protein) and for a truncated form of MalE (a periplasmic protein) were first synthesized in a membrane-depleted E. coli-derived cell-free translocation system followed by posttranslational incubation with inverted vesicles derived from the plasma membrane of E. coli. Our data thus indicate that the N and C termini of PrlA are exposed to the cytoplasm. We discuss the possibility that the transmembrane segments of PrlA could be arranged in the lipid bilayer in a cylindrical fashion, thereby delimiting a protein conducting channel, with a signal sequence binding domain represented, at least in part, by the N and C termini of PrlA. Such a channel would also contain a "stop-transfer" sequence binding domain that in response to a stop-transfer sequence would open the cylindrical channel to the lipid bilayer and permit displacement of the polypeptide from the channel to the lipid bilayer, resulting in membrane integration.
journal_name
Proc Natl Acad Sci U S Aauthors
Watanabe M,Blobel Gdoi
10.1073/pnas.86.6.1895subject
Has Abstractpub_date
1989-03-01 00:00:00pages
1895-9issue
6eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::In electron microscopy studies of the endothelial vesicles in frog mesenteric capillaries, an accidental observation was made concerning vesicular organization. When tannic acid was added to already fixed tissue, the mordant reached apparently free vesicles in the cytoplasm under conditions in which vesicular movement...
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.76.12.6439
更新日期:1979-12-01 00:00:00
abstract::We recognize, understand, and interact with objects through both vision and touch. Conceivably, these two sensory systems encode object shape in similar ways, which could facilitate cross-modal communication. To test this idea, we studied single neurons in macaque monkey intermediate visual (area V4) and somatosensory...
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.0904186106
更新日期:2009-09-22 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.93.7.2735
更新日期:1996-04-02 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.1319685111
更新日期:2014-04-15 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.0608842104
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doi:10.1073/pnas.93.25.14940
更新日期:1996-12-10 00:00:00
abstract::Dendrite morphogenesis is regulated by neuronal activity or neurotrophins, which may function by activating intrinsic signaling proteins, including Rho family GTPases. Here we report that activity- and brain-derived neurotrophic factor (BDNF)-dependent dendritic morphogenesis requires activation of geranylgeranyltrans...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.0800846105
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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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.0804286105
更新日期:2008-07-22 00:00:00
abstract::The kinase Cdc2p is a central regulator of entry into and progression through nuclear division during mitosis and meiosis in eukaryotes. Cdc2p is activated at the onset of mitosis by dephosphorylation on tyrosine-15, the phosphorylation status of which is determined mainly by the kinase Wee1p and the phosphatase Cdc25...
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.0702906104
更新日期:2007-09-11 00:00:00
abstract::A previously undescribed toothless flying reptile from northeastern China, Nemicolopterus crypticus gen. et sp. nov., was discovered in the lacustrine sediments of the Early Cretaceous Jiufotang Formation, western Liaoning, China. The specimen consists of an almost complete articulated skeleton (IVPP V14377) and, desp...
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.0707728105
更新日期:2008-02-12 00:00:00
abstract::In plants, the AUXIN RESPONSE FACTOR (ARF) transcription factor family regulates gene expression in response to auxin. In the absence of auxin, ARF transcription factors are repressed by interaction with AUXIN/INDOLE 3-ACETIC ACID (Aux/IAA) proteins. Although the C termini of ARF and Aux/IAA proteins facilitate their ...
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.1400074111
更新日期:2014-04-08 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.91.18.8378
更新日期:1994-08-30 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.95.18.10890
更新日期:1998-09-01 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.1716883115
更新日期:2018-07-17 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::In vitro T-cell receptor-induced programmed cell death in both activated T cells from human immunodeficiency virus-seronegative (HIV-) donors and resting T cells from HIV+ donors was substantially influenced by cytokines. Addition of exogenous recombinant "type 1" lymphokines interferon gamma and interleukin 2 (IL-2),...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Molecular analyses of Na,K-ATPase abundance and alpha-subunit isoform distribution were performed to determine whether pump expression varies at different points through the thickness of the circular layer of colonic smooth muscle. The mRNA and polypeptides of Na,K-ATPase alpha 1 and beta subunits were twice as abunda...
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.88.6.2370
更新日期:1991-03-15 00:00:00
abstract::The human spliceosome is a large ribonucleoprotein complex that catalyzes pre-mRNA splicing. It consists of five snRNAs and more than 200 proteins. Because of this complexity, much work has focused on the Saccharomyces cerevisiae spliceosome, viewed as a highly simplified system with fewer than half as many splicing 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.1416879112
更新日期:2015-03-17 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.1322377111
更新日期:2014-04-22 00:00:00
abstract::Axonal degeneration is an initial key step in traumatic and neurodegenerative CNS disorders. We established a unique in vivo epifluorescence imaging paradigm to characterize very early events in axonal degeneration in the rat optic nerve. Single retinal ganglion cell axons were visualized by AAV-mediated expression 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.0909794107
更新日期:2010-03-30 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
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更新日期:2005-10-18 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.65.4.781
更新日期:1970-04-01 00:00:00
abstract::Developmental and physiological responses are regulated by light throughout the entire life cycle of higher plants. To sense changes in the light environment, plants have developed various photoreceptors, including the red/far-red light-absorbing phytochromes and blue light-absorbing cryptochromes. A wide variety of p...
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.96.25.14652
更新日期:1999-12-07 00:00:00
abstract::Nonhomologous integration vectors have been used to demonstrate the feasibility of insertional mutagenesis in haploid tachyzoites of the protozoan parasite Toxoplasma gondii. Mutant clones resistant to 5-fluorouracil were identified at a frequency of approximately 10(-6) (approximately 2 x 10(-5) of the stable transfo...
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.92.12.5749
更新日期:1995-06-06 00:00:00
abstract::The biological roles of estrogen-responsive finger protein (efp) in vivo were evaluated in mice carrying a loss-of-function mutation in efp by gene-targeted mutagenesis. Although efp homozygous mice were viable and fertile in both sexes, the uterus that expressed abundant estrogen receptor alpha exhibited 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.96.21.12027
更新日期:1999-10-12 00:00:00
abstract::Experimental intramolecular vibrational dephasing transients for several large organic molecules are reanalyzed. Fits to the experimental data, as well as full numerical quantum calculations with a factorized potential surface for all active degrees of freedom of fluorene indicate that power law decays, not exponentia...
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.95.11.5965
更新日期:1998-05-26 00:00:00