Abstract:
:Phosphorylation plays a critical role in controlling the function of cytoskeletal assemblies but no direct method yet exists to measure the phosphorylation state of proteins at the level of individual molecules and assemblies. Herein, we apply scanning transmission electron microscopy in combination with electron energy loss spectroscopy to measure the distributions of mass and phosphorus in neurofilaments (NFs) isolated from the squid giant axon. We find that native squid NFs, in contrast to typical reconstituted intermediate filaments, are a relatively homogeneous population containing only eight coiled-coil dimers per cross section. The measured stoichiometry of approximately 1:1 for light/heavy peptides strongly suggests that squid NFs are composed of heterodimers. Furthermore, each heavy chain of the dimers carries at least 100 phosphate groups and is, therefore, near-maximally phosphorylated. These results also demonstrate that scanning transmission electron microscopy combined with electron energy loss spectroscopy at the nanometer scale is capable of characterizing the level and distribution of phosphorylation in individual mass-mapped protein assemblies.
journal_name
Proc Natl Acad Sci U S Aauthors
Leapman RD,Gallant PE,Reese TS,Andrews SBdoi
10.1073/pnas.94.15.7820subject
Has Abstractpub_date
1997-07-22 00:00:00pages
7820-4issue
15eissn
0027-8424issn
1091-6490journal_volume
94pub_type
杂志文章abstract::MicroRNA-34a (miR-34a) is the most highly elevated hepatic miR in obese mice and is also substantially elevated in patients who have steatosis, but its role in obesity and metabolic dysfunction remains unclear. After a meal, FGF19 is secreted from the ileum; binds to a hepatic membrane receptor complex, FGF19 receptor...
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.1205951109
更新日期:2012-10-02 00:00:00
abstract::We have studied the in vivo signaling mechanisms involved in nociceptin/orphanin FQ (Noci)-induced pain responses by using a flexor-reflex paradigm. Noci was 10,000 times more potent than substance P (SP) in eliciting flexor responses after intraplantar injection into the hind limb of mice, but the action of Noci seem...
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.95.18.10949
更新日期:1998-09-01 00:00:00
abstract::In adult mammalian brain, occurrence of the synthesis of estradiol from endogenous cholesterol has been doubted because of the inability to detect dehydroepiandrosterone synthase, P45017alpha. In adult male rat hippocampal formation, significant localization was demonstrated for both cytochromes P45017alpha and P450 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.2630225100
更新日期:2004-01-20 00:00:00
abstract::The human Thy-1 gene has been isolated and sequenced and compared to the rat and mouse Thy-1 genes. All three genes are organized in the same way: one exon encoding the majority of the signal peptide, another encoding the transmembrane segment, and a third encoding the remainder of the protein. One major structural di...
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.82.19.6657
更新日期:1985-10-01 00:00:00
abstract::Inhibitory interneurons regulate the responses of cortical circuits. In auditory cortical areas, inhibition from these neurons narrows spectral tuning and shapes response dynamics. Acute disruptions of inhibition expand spectral receptive fields. However, the effects of long-term perturbations of inhibitory circuitry ...
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.1205909109
更新日期:2012-08-21 00:00:00
abstract::Antigen receptor gene assembly is regulated by transcriptional promoters and enhancers, which control the accessibility of gene segments to a lymphocyte-specific V(D)J recombinase. However, it remained unclear whether accessibility depends on the process of transcription itself or chromatin modifications that accompan...
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.182166699
更新日期:2002-09-17 00:00:00
abstract::Dendritic cells (DCs) and B cells present antigen-derived peptides bound to MHC class II (MHC II) molecules for recognition by CD4-positive T lymphocytes. DCs control the intracellular traffic of peptide-MHC II complexes by regulating the ubiquitination of MHC II. In resting or "immature" DCs, ubiquitinated MHC II 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.1202977109
更新日期:2012-06-05 00:00:00
abstract::The role of the Ca2+/phospholipid-dependent, diacylglycerol-activated enzyme protein kinase C (PKC) in rabbit eyelid conditioning was examined. PKC was partially purified from the CA1 region of hippocampal slices from naive, pseudoconditioned, and conditioned rabbits 24 hr after the rabbits were well conditioned. Crud...
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.85.6.1988
更新日期:1988-03-01 00:00:00
abstract::In previous studies we showed that 5 days of treatment with granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) mobilized murine repopulating cells to the peripheral blood (PB) and that these cells could be efficiently transduced with retroviral vectors. We also found that, 7-14 days after cytokin...
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.93.21.11871
更新日期:1996-10-15 00:00:00
abstract::Little is known about the large ectodomain of MET, the product of the c-met protooncogene and receptor for hepatocyte growth factor/scatter factor (HGF/SF). Here, we establish by deletion mutagenesis that the HGF/SF and heparin-binding sites of MET are contained within a large N-terminal domain spanning the alpha-chai...
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.2034936100
更新日期:2003-10-14 00:00:00
abstract::We have used oligonucleotide-directed mutagenesis to make a specific change in the beta-lactamase (EC 3.5.2.6) (ampicillin resistance) gene of the plasmid pBR322. Evidence suggests that the active site for this enzyme may include a serine-threonine dyad (residues 70 and 71). By priming in vitro DNA synthesis with a ch...
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.79.21.6409
更新日期:1982-11-01 00:00:00
abstract::The anti-inflammatory activity of intravenous Ig (IVIG) results from a minor population of the pooled IgG molecules that contains terminal alpha2,6-sialic acid linkages on their Fc-linked glycans. These anti-inflammatory properties can be recapitulated with a fully recombinant preparation of appropriately sialylated I...
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.0810163105
更新日期:2008-12-16 00:00:00
abstract::Naive CD4 T cells differentiate into several effector lineages, which generate a stronger and more rapid response to previously encountered immunological challenges. Although effector function is a key feature of adaptive immunity, the molecular basis of this process is poorly understood. Here, we investigated the spa...
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.1502461112
更新日期:2015-03-31 00:00:00
abstract::Recombinant plasmids containing mutant or wild-type adenovirus serotype 2 EIa genes that produce the 12S mRNA alone, the 13S mRNA alone, or both mRNAs were cotransfected into HeLa cells with plasmids containing the viral EIIa or EIII transcription units. The amount of RNA produced from the EIIa and EIII promoters was ...
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.81.14.4381
更新日期:1984-07-01 00:00:00
abstract::DNA sequences containing short adenine tracts are intrinsically curved and play a role in transcriptional regulation. Despite many high-resolution NMR and x-ray studies, the origins of curvature remain disputed. Long-range restraints provided by 85 residual dipolar couplings were measured for a DNA decamer containing ...
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.0437877100
更新日期:2003-03-04 00:00:00
abstract::The very low density lipoprotein (VLDL) receptor is a recently cloned member of the low density lipoprotein (LDL) receptor family that mediates the binding and uptake of VLDL when overexpressed in animal cells. Its sequence is 94% identical in humans and rabbits and 84% identical in humans and chickens, implying a con...
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.92.18.8453
更新日期:1995-08-29 00:00:00
abstract::Endothelial cell growth factor (ECGF) binds specifically in vitro to membrane receptors present on the surface of several cell types, including murine and human endothelial cells and fibroblasts. Monoclonal antibodies prepared against ECGF that inhibit the mitogenic activity of the growth factor prevent receptor occup...
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.82.18.6138
更新日期:1985-09-01 00:00:00
abstract::Immunological memory is a hallmark of adaptive immunity, and understanding T cell memory will be central to the development of effective cell-mediated vaccines. The characteristics and functions of CD4 memory cells have not been well defined. Here we demonstrate that the increased size of the secondary response is sol...
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.0807449105
更新日期:2008-09-23 00:00:00
abstract::Electromyographic recordings from individual identified ankle muscles of the 7-day chick embryo (stage 31) were used to determine the organization of motor output at a developmental stage shortly after the onset of spontaneous motility in the leg. During spontaneous motility of the embryo, the electromyographic record...
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.72.4.1245
更新日期:1975-04-01 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.080572297
更新日期:2000-05-09 00:00:00
abstract::Despite the importance of tryptophan (Trp) radicals in biology, very few radicals have been trapped and characterized in a physiologically meaningful context. Here we demonstrate that the diheme enzyme MauG uses Trp radical chemistry to catalyze formation of a Trp-derived tryptophan tryptophylquinone cofactor on its 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.1215011110
更新日期:2013-03-19 00:00:00
abstract::Mice lacking the beta1-subunit (gene, Kcnmb1; protein, BK-beta1) of the large Ca-activated K channel (BK) are hypertensive. This phenotype is thought to result from diminished BK currents in vascular smooth muscle where BK-beta1 is an ancillary subunit. However, the beta1-subunit is also expressed in the renal connect...
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.0904635106
更新日期:2009-07-14 00:00:00
abstract::A central problem in understanding enzyme regulation is to define the conformational states that account for allosteric changes in catalytic activity. For Escherichia coli aspartate transcarbamoylase (ATCase; EC) the active, relaxed (R state) holoenzyme is generally assumed to be represented by the crystal structure o...
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.090087197
更新日期:2000-05-09 00:00:00
abstract::Many cell surface receptors are multimeric proteins, composed of several structural domains, some involved in ligand recognition, whereas others are responsible for signal transduction. In most cases, the mechanism of how ligand interaction in the extracellular domains leads to the activation of effector domains remai...
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.1107775108
更新日期:2011-09-13 00:00:00
abstract::Prolonged incubation of NIH 3T3 cells under the growth constraint of confluence results in a persistent impairment of proliferation when the cells are subcultured at low density and a greatly increased probability of neoplastic transformation in assays for transformation. These properties, along with the large accumul...
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.93.18.9793
更新日期:1996-09-03 00:00:00
abstract::IL-7 and thymic stromal lymphopoietin (TSLP) are two major cytokines controlling murine B cell development. IL-7 has been studied extensively, but only recently has it become possible to unravel the role of TSLP in detail. We studied the biological activities of TSLP in B cell development at distinct ages in the mouse...
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.0402919101
更新日期:2004-07-27 00:00:00
abstract::Myosin V, a double-headed molecular motor, transports organelles within cells by walking processively along actin, a process that requires coordination between the heads. To understand the mechanism underlying this coordination, processive runs of single myosin V molecules were perturbed by varying nucleotide content....
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.0307247101
更新日期:2004-04-13 00:00:00
abstract::Cytochromes P450 play key roles in drug metabolism and disease by oxidizing a wide variety of natural and xenobiotic compounds. High-resolution crystal structures of P450cam bound to ruthenium sensitizer-linked substrates reveal an open conformation of the enzyme that allows substrates to access the active center via ...
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.221297998
更新日期:2001-10-23 00:00:00
abstract::Incubation of O6-[3H]ethylguanine-containing DNA with a rat liver chromatin fraction resulted in a decrease in the O6-ethylguanine content of the DNA. Analysis of the products of this reaction showed that the ethyl group had been transferred from the O6-ethylguanine to a protein acceptor. When the incubation mixture 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.78.11.6766
更新日期:1981-11-01 00:00:00
abstract::Transcription in the human immunodeficiency virus type 1 (HIV-1) retrovirus is regulated by binding the viral Tat protein (trans-acting transcriptional activator) to the trans-activation response (TAR) RNA sequence. Here, vacuum UV circular dichroism (VUV-CD) is used to study the structure of TAR and its complex 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.89.20.9734
更新日期:1992-10-15 00:00:00