Abstract:
:Earlier Monte Carlo studies on a single-helix model of the GTP cap at the end of a microtubule are extended here to a more realistic five-start helix model of the microtubule end. As in the earlier work, phase changes occur at the microtubule end: the end is either capped with GTP and growing slowly or uncapped and shortening rapidly, and these two regimes alternate (at a given tubulin concentration) at steady state. Macroscopic rate constants for the two-phase model are deduced from the Monte Carlo results. The macroscopic rate constants lead to properties that are in semiquantitative agreement with related experiments of Mitchison and Kirschner.
journal_name
Proc Natl Acad Sci U S Aauthors
Chen YD,Hill TLdoi
10.1073/pnas.82.4.1131subject
Has Abstractpub_date
1985-02-01 00:00:00pages
1131-5issue
4eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::During the periimplantation period of pregnancy, pig blastocysts undergo morphological changes and differentiation requiring secretion and transport of nutrients (histotroph) into the uterine lumen. Of these nutrients, glucose is converted to fructose, an isomer of glucose, by conceptus trophectoderm. Although glucose...
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.1204298109
更新日期:2012-06-19 00:00:00
abstract::In humans, spontaneous movements are often preceded by early brain signals. One such signal is the readiness potential (RP) that gradually arises within the last second preceding a movement. An important question is whether people are able to cancel movements after the elicitation of such RPs, and if so until which po...
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.1513569112
更新日期:2016-01-26 00:00:00
abstract::We investigated the manner in which the sea urchin larva takes up calcium from its body cavity into the primary mesenchymal cells (PMCs) that are responsible for spicule formation. We used the membrane-impermeable fluorescent dye calcein and alexa-dextran, with or without a calcium channel inhibitor, and imaged the la...
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.1612017113
更新日期:2016-11-08 00:00:00
abstract::Oligomerization plays a critical role in shaping the light-harvesting properties of many photosynthetic pigment-protein complexes, but a detailed understanding of this process at the level of individual pigments is still lacking. To study the effects of oligomerization, we designed a single-molecule approach to probe ...
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.1514027112
更新日期:2015-11-10 00:00:00
abstract::Profiling the dynamic interaction of p300 with proximal promoters of human T cells identified a class of genes that rapidly coassemble p300 and RNA polymerase II (pol II) following mitogen stimulation. Several of these p300 targets are immediate early genes, including FOS, implicating a prominent role for p300 in the ...
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.0905469106
更新日期:2009-11-17 00:00:00
abstract::In this study we compared the cellular concentrations and stability of the mRNA transcribed from the aprE (subtilisin) gene (a gene preferentially expressed in stationary growth phase) with those of a vegetative mRNA, succinate dehydrogenase (SDH) mRNA. The subtilisin transcript was shown to be at least 3 times more 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.87.21.8355
更新日期:1990-11-01 00:00:00
abstract::alpha-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-type glutamate receptors undergo constitutive and ligand-induced internalization that requires dynamin and the clathrin adaptor complex AP-2. We report here that an atypical basic motif within the cytoplasmic tails of AMPA-type glutamate receptors directl...
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.0611170104
更新日期:2007-02-20 00:00:00
abstract::A 6.1-kilobase insertion into the rudimentary (r) gene was cloned and partially sequenced. The insertion consists of a 703-base-pair (bp) P element next to a 5.4-kilobase single-copy sequence. The normal position of the single-copy sequence is near the tip of the X chromosome. Upon insertion into the r gene, this chim...
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.88.3.693
更新日期:1991-02-01 00:00:00
abstract::Arteriovenous (AV) malformation (AVM) is a devastating condition characterized by focal lesions of enlarged, tangled vessels that shunt blood from arteries directly to veins. AVMs can form anywhere in the body and can cause debilitating ischemia and life-threatening hemorrhagic stroke. The mechanisms that underlie AVM...
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.1415316111
更新日期:2014-12-16 00:00:00
abstract::At the neuromuscular junction, two motor neuron-derived signals have been implicated in the regulation of synaptogenesis. Neuregulin-1 is thought to induce transcription of acetylcholine receptor (AChR) genes in subsynaptic muscle nuclei by activating ErbB receptors. Neural agrin aggregates AChRs by activating the rec...
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.251291598
更新日期:2001-12-04 00:00:00
abstract::The failure to induce self-tolerance of simian virus 40 large tumor antigen (T antigen) expressed in the pancreatic beta cells of transgenic mice results in an autoimmune response against this protein and the cells that synthesize it. In every transgenic mouse with delayed onset of T-antigen expression and consequent ...
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.87.19.7487
更新日期:1990-10-01 00:00:00
abstract::The sequence of the transforming region of simian sarcoma virus (SSV) has been determined by using molecularly cloned viral DNA. This region encompassed the 1.0-kilobase pair woolly monkey cell-derived insertion sequence, v-sis, and flanking simian sarcoma-associated viral (SSAV) sequences. A 675-nucleotide-long open ...
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.79.10.3179
更新日期:1982-05-01 00:00:00
abstract::The temperature coefficient of equilibrium isotope fractionation in the heavy elements is shown to be larger at high temperatures than that expected from the well-studied vibrational isotope effects. The difference in the isotopic behavior of the heavy elements as compared with the light elements is due to the large n...
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.93.18.9393
更新日期:1996-09-03 00:00:00
abstract::The human gut is home to trillions of microbes, thousands of bacterial phylotypes, as well as hydrogen-consuming methanogenic archaea. Studies in gnotobiotic mice indicate that Methanobrevibacter smithii, the dominant archaeon in the human gut ecosystem, affects the specificity and efficiency of bacterial digestion 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.0704189104
更新日期:2007-06-19 00:00:00
abstract::The actin cytoskeleton is an essential intracellular filamentous structure that underpins cellular transport and cytoplasmic streaming in plant cells. However, the system-level properties of actin-based cellular trafficking remain tenuous, largely due to the inability to quantify key features of the actin cytoskeleton...
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.1706711114
更新日期:2017-07-11 00:00:00
abstract::Albatrosses (Diomedeidae) do not occur in the North Atlantic Ocean today except as vagrants, although five species were present in the early Pliocene. No fossil breeding sites of albatrosses were known previously. The timing of extinction of albatrosses in the North Atlantic was likewise unknown. Deposits that formed ...
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.1934576100
更新日期:2003-10-28 00:00:00
abstract::C-tail-anchored (TA) proteins often require a transmembrane domain of moderate hydrophobicity to maintain their endoplasmic reticulum residence, but the suggested role of protein-lipid interactions in this phenomenon has not been established. Here, we studied the interaction of TA proteins with lipids by differential ...
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.0508157102
更新日期:2005-11-08 00:00:00
abstract::Patchy particles with shape complementarity can serve as building blocks for assembling colloidal superstructures. Alternatively, encoding information on patches using DNA can direct assembly into a variety of crystalline or other preprogrammed structures. Here, we present a tool where DNA is used both to engineer sha...
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.1918504117
更新日期:2020-05-19 00:00:00
abstract::The mammalian form of the protozoan parasite Leishmania mexicana contains high activity of a cysteine proteinase (LmCPb) encoded on a tandem array of 19 genes (lmcpb). Homozygous null mutants for lmcpb have been produced by targeted gene disruption. All life-cycle stages of the mutant can be cultured in vitro, demonst...
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.93.12.6008
更新日期:1996-06-11 00:00:00
abstract::Human cells express thousands of different surface proteins that can be used for cell classification, or to distinguish healthy and disease conditions. A method capable of profiling a substantial fraction of the surface proteome simultaneously and inexpensively would enable more accurate and complete classification 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.1721899115
更新日期:2018-03-13 00:00:00
abstract::During Drosophila development, nuclear and cell divisions are coordinated in response to developmental signals. In yeast and mammalian cells, signals that control cell division regulate the activity of cyclin-dependent kinases (Cdks) through proteins such as cyclins that interact with the Cdks. Here we describe two Dr...
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.93.7.3011
更新日期:1996-04-02 00:00:00
abstract::Precise genome editing is a valuable tool to study gene function in model organisms. Prime editing, a precise editing system developed in mammalian cells, does not require double-strand breaks or donor DNA and has low off-target effects. Here, we applied prime editing for the model organism Drosophila melanogaster and...
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.2021996118
更新日期:2021-01-05 00:00:00
abstract::A novel type I transmembrane protein of COPI-coated vesicles, p23, has been demonstrated to be localized mainly to the Golgi complex. This protein and p24, another member of the p24 family, have been shown to bind coatomer via their short cytoplasmic tails. Here we demonstrate that p23 continuously cycles through the ...
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.94.21.11393
更新日期:1997-10-14 00:00:00
abstract::Drug resistance testing has been shown to be beneficial for clinical management of HIV type 1 infected patients. Whereas phenotypic assays directly measure drug resistance, the commonly used genotypic assays provide only indirect evidence of drug resistance, the major challenge being the interpretation of the sequence...
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.112177799
更新日期:2002-06-11 00:00:00
abstract::The levels of c-myc, c-fos, and JE mRNAs accumulate in a biphasic pattern following infection of quiescent BALB/c 3T3 mouse cells with polyomavirus. Maximal levels of c-myc and c-fos mRNAs were seen within 1 hr and were nearly undetectable at 6 hr after infection. At 12 hr after infection mRNA levels were again maxima...
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.84.5.1210
更新日期:1987-03-01 00:00:00
abstract::An epithelial cell line, designated COMMA-1D, was derived from mammary tissue of BALB/c mice in the middle of pregnancy. This line, in continuous cell culture for 12 months, exhibits several characteristics distinctive of normal mammary epithelial cells, including induction of casein synthesis in vitro and normal duct...
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.81.12.3756
更新日期:1984-06-01 00:00:00
abstract::Previous studies implicate the hypothalamic ventromedial nucleus (VMN) in glycemic control. Here, we report that selective inhibition of the subset of VMN neurons that express the transcription factor steroidogenic-factor 1 (VMN(SF1) neurons) blocks recovery from insulin-induced hypoglycemia whereas, conversely, activ...
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.1521160113
更新日期:2016-04-05 00:00:00
abstract::Mutations in a number of stress granule-associated proteins have been linked to various neurodegenerative diseases. Several of these mutations are found in aggregation-prone prion-like domains (PrLDs) within these proteins. In this work, we examine the sequence features governing PrLD localization to stress granules u...
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.1912723117
更新日期:2020-03-17 00:00:00
abstract::The surface layer of the oceans and other aquatic environments contains many bacteria that range in activity, from dormant cells to those with high rates of metabolism. However, little experimental evidence exists about the activity of specific bacterial taxa, especially rare ones. Here we explore the relationship bet...
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.1101405108
更新日期:2011-08-02 00:00:00
abstract::It is becoming clear that steroids can be synthesized de novo by the brain and other nervous systems. Such steroids are called neurosteroids, and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. In this study, we show that the newt brain actively produces 7alpha-hydroxypregne...
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.0407176101
更新日期:2004-12-07 00:00:00