Abstract:
:We have earlier proposed a molecular mechanism for the translocation of hydrophilic proteins across membranes that accounts for the experimental facts and meets the restrictions that we stipulate for such a mechanism. In particular, the restrictions are that translocation occurs by successive segments of the polypeptide chain and that the ionic groups of the polypeptide remain in contact with water throughout the translocation process. The evidence indicates that the transfer of integral proteins into membranes very likely uses the same molecular machinery as does the translocation of hydrophilic proteins across membranes. Here we show how the mechanism we have proposed for translocation can also be utilized in the intercalation of known types of integral proteins, accounting for their specific topologies in the membrane.
journal_name
Proc Natl Acad Sci U S Aauthors
Singer SJ,Maher PA,Yaffe MPdoi
10.1073/pnas.84.7.1960subject
Has Abstractpub_date
1987-04-01 00:00:00pages
1960-4issue
7eissn
0027-8424issn
1091-6490journal_volume
84pub_type
杂志文章abstract::We have measured the opioid receptor reserve in the guinea pig ileum myenteric plexus by means of the site-directed alkylating agent, beta-chlornaltrexamine. Treatment of the tissue with low (less than 10 nM) concentrations of beta-chlornaltrexamine caused a parallel shift of the log concentration-response curves for ...
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.81.22.7253
更新日期:1984-11-01 00:00:00
abstract::Chromogranin A (CGA) is a secretory protein present in the adrenal medulla and in a variety of endocrine organs. This protein may serve as precursor for pancreastatin (PST) and for other biologically active peptides. Recently, chromostatin (CST), a CGA derivative, has been identified that possesses high biological act...
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.90.6.2360
更新日期:1993-03-15 00:00:00
abstract::Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face-object associations were scanned during passive rest and during encoding of new related and unre...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章
doi:10.1073/pnas.1404396111
更新日期:2014-11-04 00:00:00
abstract::Partial amino acid sequence of the Ia molecule encoded by the I-E or I-C (I-EC) subregion of the major histocompatibility complex of the mouse are presented. The Ia molecule appears to be comprised of two noncovalently associated polypeptides. The larger subunit, alpha, has an approximate molecular weight of 35,000 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.74.11.5135
更新日期:1977-11-01 00:00:00
abstract::Development of effective chemopreventive agents against prostate cancer (CaP) for humans requires conclusive evidence of their efficacy in animal models that closely emulates human disease. The autochthonous transgenic adenocarcinoma of the mouse prostate (TRAMP) model, which spontaneously develops metastatic CaP, is ...
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.171326098
更新日期:2001-08-28 00:00:00
abstract::By double indirect immunofluorescence, using primary rabbit antibodies to tubulin and guinea pig antibodies to vimentin, we have simultaneously labeled microtubules and intermediate filaments in several types of cultured normal fibroblasts. With well-spread interphase cells there was an extensive but not complete corr...
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.78.11.6986
更新日期:1981-11-01 00:00:00
abstract::Working memory (WM) is the ability to retain and associate information over brief time intervals. Functional imaging studies demonstrate that WM is mediated by a distributed network including frontal and posterior cortices, hippocampus, and cerebellum. In rodents, the presentation of stimuli in a WM task is followed b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1073/pnas.97.2.919
更新日期:2000-01-18 00:00:00
abstract::We analyzed the relationship of genetic factors determining the expression of endogenous type-C RNA tumor viruses and other host-gene markers to tumorigenesis. A hybridization experiment was performed with mice of strains AKR/J and C57L, the first filial (F(1)) generation hybrids, the second filial (F(2)) generation 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.70.5.1450
更新日期:1973-05-01 00:00:00
abstract::A small number of facial expressions may be universal in that they are produced by the same basic affective states and recognized as such throughout the world. However, other aspects of emotionally expressive behavior vary widely across culture. Just why do they vary? We propose that some cultural differences in expre...
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.1413661112
更新日期:2015-05-12 00:00:00
abstract::Cytochrome P450 monooxygenases (P450) in the honey bee, Apis mellifera, detoxify phytochemicals in honey and pollen. The flavonol quercetin is found ubiquitously and abundantly in pollen and frequently at lower concentrations in honey. Worker jelly consumed during the first 3 d of larval development typically contains...
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.1614864114
更新日期:2017-03-07 00:00:00
abstract::The ability of materials to define the architecture and microenvironment experienced by cells provides new opportunities to direct the fate of human pluripotent stem cells (HPSCs) [Robinton DA, Daley GQ (2012) Nature 481(7381):295-305]. However, the conditions required for self-renewal vs. differentiation of HPSCs are...
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.1319685111
更新日期:2014-04-15 00:00:00
abstract::Long interspersed nuclear elements 1 (L1) are active retrotransposons that reside in many species, including humans and rodents. L1 elements produce an RNA intermediate that is reverse transcribed to DNA and inserted in a new genomic location. We have tagged an active human L1 element (L1(RP)) with a gene encoding enh...
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.0337627100
更新日期:2003-02-18 00:00:00
abstract::The human intestine is densely populated by a microbial consortium whose metabolic activities are influenced by, among others, bifidobacteria. However, the genetic basis of adaptation of bifidobacteria to the human gut is poorly understood. Analysis of the 2,214,650-bp genome of Bifidobacterium bifidum PRL2010, a stra...
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.1011100107
更新日期:2010-11-09 00:00:00
abstract::Viruses are fundamental components of marine microbial communities that significantly influence oceanic productivity, biogeochemistry, and ecosystem processes. Despite their importance, the temporal activities and dynamics of viral assemblages in natural settings remain largely unexplored. Here we report the transcrip...
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.1714821114
更新日期:2017-10-24 00:00:00
abstract::Asymmetric cell division (ACD) is believed to be a physiological event that occurs during development and tissue homeostasis in a large variety of organisms. ACD produces two unequal daughter cells, one of which resembles a multipotent stem and/or progenitor cell, whereas the other has potential for differentiation. 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.1205525109
更新日期:2012-10-30 00:00:00
abstract::Two-dimensional gel electrophoresis has allowed the detection of proteins characteristic of inner cell mass and trophectoderm in mouse blastocyst. Certain of the proteins characterizing trophectoderm copurify with intermediate filaments from trophectoderm and a trophoblastoma cell line. A monoclonal antibody prepared ...
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.77.7.4113
更新日期:1980-07-01 00:00:00
abstract::We have examined the affinity of two recently synthesized flavin analogs for the isoalloxazine binding site of riboflavin-binding protein (RBP). The results showed that pyrimidopteridines could bind to RBP (Kd 160-250 microM). This suggested that, at the FMN or FAD level, these analogs might also bind to other apoflav...
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.81.14.4246
更新日期:1984-07-01 00:00:00
abstract::Superficial cells from early amphibian embryos display regional specializations of their cell surfaces. That portion of the plasma membrane facing the perivitelline space (apical surface) is nonadhesive, whereas, in the same cell, the lateral and basal portions of the plasma membrane will adhere to other cells. 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.77.6.3460
更新日期:1980-06-01 00:00:00
abstract::Myosin-binding protein C (MyBP-C) is an accessory protein of striated muscle thick filaments and a modulator of cardiac muscle contraction. Defects in the cardiac isoform, cMyBP-C, cause heart disease. cMyBP-C includes 11 Ig- and fibronectin-like domains and a cMyBP-C-specific motif. In vitro studies show that in addi...
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.1316001111
更新日期:2014-02-11 00:00:00
abstract::Estrogen signaling occurs through at least two distinct molecular pathways: (i) direct binding of liganded estrogen receptors (ERs) to estrogen-responsive DNA elements (EREs) (the "ER/ERE pathway") and (ii) indirect recruitment of liganded ERs to activating protein-1 (AP-1)-responsive DNA elements via heterodimers 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.0407113102
更新日期:2005-01-18 00:00:00
abstract::Theory predicts that double-core-hole (DCH) spectroscopy can provide a new powerful means of differentiating between similar chemical systems with a sensitivity not hitherto possible. Although DCH ionization on a single site in molecules was recently measured with double- and single-photon absorption, double-core hole...
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.1111380108
更新日期:2011-10-11 00:00:00
abstract::The role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial, and the effect of climatic variability, in particular, has largely been ignored. For instance, it was recently revealed that the proposed link between climate change and widespread amphibian...
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.0912883107
更新日期:2010-05-04 00:00:00
abstract::Aberrant promoter hypermethylation is frequently observed in cancer. The potential for this mechanism to contribute to tumor development depends on whether the genes affected are repressed because of their methylation. Many aberrantly methylated genes play important roles in development and are bivalently marked in ES...
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.1013224108
更新日期:2011-03-15 00:00:00
abstract::Lipid rafts are important signaling platforms in T cells. Little is known about their properties in human CD8(+) T cells. We studied polarization of lipid rafts by digital immunofluorescence microscopy in primary human T cells, using beads coated with anti-CD3 and anti-CD28 mAbs (CD3/28 beads). Unlike CD4(+) T cells, ...
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.232058599
更新日期:2002-11-12 00:00:00
abstract::Nucleotide sequence analysis of one of several tRNA genes cloned from Tetrahymena thermophila macronuclear DNA indicated that it corresponds to a tRNA species having TTA as anticodon. Subsequently, the tRNA species corresponding to that gene was isolated and its nucleotide sequence was determined by post-labeling tech...
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.82.14.4758
更新日期:1985-07-01 00:00:00
abstract::Miraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, strong sweetness is sensed over 1 h each time we taste a sour solution. Neverthel...
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.1016644108
更新日期:2011-10-04 00:00:00
abstract::The proteolytic cleavage of sterol regulatory element-binding proteins (SREBPs) is regulated by SREBP cleavage-activating protein (SCAP), which forms complexes with SREBPs in membranes of the endoplasmic reticulum (ER). In sterol-depleted cells, SCAP facilitates cleavage of SREBPs by Site-1 protease, thereby initiatin...
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.96.20.11235
更新日期:1999-09-28 00:00:00
abstract::Glu-126 (helix IV) and Arg-144 (helix V) are charge paired and play a critical role in substrate binding in the lactose permease of Escherichia coli. When Glu-126 is replaced with Asp, the permease has relatively high activity, implying that helix V has sufficient flexibility to allow Arg-144 to accommodate the decrea...
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.96.20.11178
更新日期:1999-09-28 00:00:00
abstract::Two-dimensional gel electrophoresis of immunoprecipitated human HLA-DR antigens from cells expressing the HLA-DR4 haplotype shows distinct clustering of beta-chain patterns. Six unique electrophoretic variants were observed among 17 HLA-DR4 homozygous cell lines (HCL) analyzed. These patterns correlate precisely with ...
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.80.22.6962
更新日期:1983-11-01 00:00:00
abstract::Intense proteolysis of cytoskeletal proteins occurs in brain within minutes of transient ischemia, possibly because of the activation of calcium-sensitive proteases (calpains). This proteolytic event precedes overt signs of neuronal degeneration, is most pronounced in regions of selective neuronal vulnerability, and c...
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.88.16.7233
更新日期:1991-08-15 00:00:00