Abstract:
:A rigorous numerical test of a hypothetical mechanism of a molecular motor should model explicitly the diffusive motion of the motor's degrees of freedom as well as the transition rates between the motor's chemical states. We present such a Brownian dynamics, mechanochemcial model of the coarse-grain structure of the dimeric, linear motor myosin V. Compared with run-length data, our model provides strong support for a proposed strain-controlled gating mechanism that enhances processivity. We demonstrate that the diffusion rate of a detached motor head during motor stepping is self-consistent with known kinetic rate constants and can explain the motor's key performance features, such as speed and stall force. We present illustrative and realistic animations of motor stepping in the presence of thermal noise. The quantitative success and illustrative power of this type of model suggest that it will be useful in testing our understanding of a range of biological and synthetic motors.
journal_name
Proc Natl Acad Sci U S Aauthors
Craig EM,Linke Hdoi
10.1073/pnas.0908192106subject
Has Abstractpub_date
2009-10-27 00:00:00pages
18261-6issue
43eissn
0027-8424issn
1091-6490pii
0908192106journal_volume
106pub_type
杂志文章abstract::Cryptococcus neoformans (CN), an encapsulated, ubiquitous environmental yeast, is pathogenic for humans, primarily those with compromised immune function. CN is believed to be a facultative intracellular pathogen. Time-lapsed video microscopy revealed that yeast began to replicate and divide 2 hours after ingestion by...
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.052702799
更新日期:2002-03-05 00:00:00
abstract::We have demonstrated that the entire murine N-myc gene and the sequences necessary for its expression in human neuroblastoma cells are contained within a 7.4-kilobase murine genomic clone. The complete nucleotide sequence of this gene reveals a number of striking similarities and differences when compared to the relat...
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.83.6.1827
更新日期:1986-03-01 00:00:00
abstract::In higher eukaryotic cells, mitochondria are essential subcellular organelles for energy production, cell signaling, and the biosynthesis of biomolecules. The mitochondrial DNA (mtDNA) genome is indispensable for mitochondrial function because it encodes protein subunits of the electron transport chain and a full set ...
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.1911252116
更新日期:2019-09-03 00:00:00
abstract::Electron cryomicroscopy (cryo-EM) has been used to determine the atomic coordinates (models) from density maps of biological assemblies. These models can be assessed by their overall fit to the experimental data and stereochemical information. However, these models do not annotate the actual density values of the atom...
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.1621152114
更新日期:2017-03-21 00:00:00
abstract::The deadly symptoms of malaria occur as Plasmodium parasites replicate within blood cells. Members of several variant surface protein families are expressed on infected blood cell surfaces. Of these, the largest and most ubiquitous are the Plasmodium-interspersed repeat (PIR) proteins, with more than 1,000 variants in...
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.2016775117
更新日期:2020-12-15 00:00:00
abstract::In maturing T lineage cells, the helix-loop-helix protein E47 has been shown to enforce a critical proliferation and developmental checkpoint commonly referred to as beta selection. To examine how E47 regulates cellular expansion and developmental progression, we have used an E2A-deficient lymphoma cell line and DNA m...
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.0603728103
更新日期:2006-06-27 00:00:00
abstract::The fungus, Phycomyces blakesleeanus, shows many well-defined responses to a number of external stimuli. Genetic analysis shows that at least eight genes are involved in Phycomyces sensory transduction. As a first step toward the molecular analysis of these genes and their products, we have developed a transformation ...
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.83.19.7344
更新日期:1986-10-01 00:00:00
abstract::Serpentine barrens represent extreme hazards for plant colonists. These sites are characterized by high porosity leading to drought, lack of essential mineral nutrients, and phytotoxic levels of metals. Nevertheless, nature forged populations adapted to these challenges. Here, we use a population-based evolutionary ge...
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.1600405113
更新日期:2016-07-19 00:00:00
abstract::CD4(+) T cells expand after transfer into lymphopenic H-2(b) A(beta)-/- mice (I-A(beta)-, I-E(alpha)-deficient mice) but not after transfer into lymphopenic MHC II(Delta/Delta) mice (I-A(alpha)-, I-A(beta)-, I-E(alpha)-, and I-E(beta)-deficient mice), implying that in H-2(b) A(beta)-/- mice, A(alpha) chain and E(beta)...
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.1037754100
更新日期:2003-05-13 00:00:00
abstract::Sponges (Porifera), the simplest and earliest multicellular organisms, are thought to have evolved from their unicellular ancestors about 1 billion years ago by developing cell-recognition and adhesion mechanisms to discriminate against "non-self." Consequently, they are used as models for investigating recognition ph...
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.151111298
更新日期:2001-07-31 00:00:00
abstract::Assembly of light-harvesting complexes requires synchronization of chlorophyll (Chl) biosynthesis with biogenesis of light-harvesting Chl a/b-binding proteins (LHCPs). The chloroplast signal recognition particle (cpSRP) pathway is responsible for transport of nucleus-encoded LHCPs in the stroma of the plastid and thei...
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.1719645115
更新日期:2018-04-10 00:00:00
abstract::It is shown that a stereochemical correspondence between two molecular systems can be represented by a commuting diagram of the point groups and permutation groups involved. The effect of the diagrammatic condition on the mappings of the cosets, double cosets, subgroup lattice, and double coset algebra determined 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.72.6.2385
更新日期:1975-06-01 00:00:00
abstract::The reversible association of alpha and beta gamma subunits of GTP-binding proteins is important for signal transmission from a variety of cell-surface receptors to intracellular effectors. Previous work showed that 1,6-bis(maleimido)hexane, which crosslinks cysteine residues, crosslinks alpha o and alpha i-1 to beta ...
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.90.21.10295
更新日期:1993-11-01 00:00:00
abstract::Seed development in plants involves the coordinated growth of the embryo, endosperm, and maternal tissue. Several genes have been identified that influence seed size by acting maternally, such as AUXIN RESPONSE FACTOR2, APETALA2, and DA1. However, given the lack of gain-of-function effects of these genes on seed size,...
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.0907024106
更新日期:2009-11-24 00:00:00
abstract::A variety of agricultural plant species, including corn, respond to insect herbivore damage by releasing large quantities of volatile compounds and, as a result, become highly attractive to parasitic wasps that attack the herbivores. An elicitor of plant volatiles, N-(17-hydroxylinolenoyl)-L-glutamine, named volicitin...
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.95.23.13971
更新日期:1998-11-10 00:00:00
abstract::Acquired immunity to Streptococcus pneumoniae (pneumococcus) has long been assumed to depend on the presence of anticapsular antibodies. We found, however, that colonization with live pneumococci of serotypes 6B, 7F, or 14 protected mice against recolonization by any of the serotypes and that protection from acquisiti...
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.0501254102
更新日期:2005-03-29 00:00:00
abstract::The exceptional sensitivity of Mycobacterium tuberculosis to isonicotinic acid hydrazide (INH) lacks satisfactory definition. M. tuberculosis is a natural mutant in oxyR, a central regulator of peroxide stress response. The ahpC gene, which encodes a critical subunit of alkyl hydroperoxide reductase, is one of the tar...
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.93.23.13212
更新日期:1996-11-12 00:00:00
abstract::In the mitochondrial genome of the hemichordate Balanoglossus carnosus, the codon AAA, which is assigned to lysine in most metazoans but to asparagine in echinoderms, is absent. Furthermore, the lysine tRNA gene carries an anticodon substitution that renders its gene product unable to decode AAA codons, whereas the as...
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.95.7.3703
更新日期:1998-03-31 00:00:00
abstract::The poly(A) site of bovine prolactin (bPRL) mRNA was examined by phased priming of cDNA synthesis with oligodeoxynucleotides of the general sequence d(pT8-N-N'). The existence of multiple poly(A)-adjacent sequences in bPRL mRNA was indicated by the production of specific chain-termination fragments with at least three...
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.79.2.223
更新日期:1982-01-01 00:00:00
abstract::The functions of neurotransmitters in fetal development are poorly understood. Genetic observations have suggested a role for the inhibitory amino acid neurotransmitter gamma-aminobutyric acid (GABA) in the normal development of the mouse palate. Mice homozygous for mutations in the beta-3 GABAA receptor subunit devel...
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.94.21.11451
更新日期:1997-10-14 00:00:00
abstract::Hairs, feathers, and scales normally exhibit precise orientations with respect to the body axes. In Frizzled6 (Fz6)(-/-) mice, the global orientation of hair follicles is disrupted, leading to waves, whorls, and tufts, each comprising many hundreds of hairs. By analyzing the orientation of developing hair follicles, 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.0609712104
更新日期:2006-12-26 00:00:00
abstract::p90 ribosomal S6 kinase (RSK1) is an effector of both Ras/MEK/MAPK and PI3K/PDK1 pathways. We present evidence that RSK1 drives p27 phosphorylation at T198 to increase RhoA-p27 binding and cell motility. RSK1 activation and p27pT198 both increase in early G(1). As for many kinase-substrate pairs, cellular RSK1 copreci...
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.0805057106
更新日期:2009-06-09 00:00:00
abstract::Actin polymerization and assembly into stress fibers (SFs) is central to many cellular processes. However, how SFs form in response to the mechanical interaction of cells with their environment is not fully understood. Here we have identified Piezo2 mechanosensitive cationic channel as a transducer of environmental ph...
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.1718177115
更新日期:2018-02-20 00:00:00
abstract::Various biological processes exhibit characteristics that vary dramatically in response to different input conditions or changes in the history of the process itself. One of the examples studied here, the Ras-PKC-mitogen-activated protein kinase (MAPK) bistable pathway, follows two distinct dynamics (modes) depending ...
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.0500554102
更新日期:2005-05-03 00:00:00
abstract::Populations of isogenic embryonic stem cells or clonal bacteria often exhibit extensive phenotypic heterogeneity that arises from intrinsic stochastic dynamics of cells. The phenotypic state of a cell can be transmitted epigenetically in cell division, leading to correlations in the states of cells related by descent....
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.1504407112
更新日期:2015-05-05 00:00:00
abstract::In facultative photoperiodic flowering plants, noninductive photoperiods result in a delay in flowering, but such plants eventually flower, illustrating plasticity in an important developmental transition, flowering. The model plant, Arabidopsis, has a facultative photoperiod response. Although the inductive flowering...
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.1010834107
更新日期:2010-09-28 00:00:00
abstract::Disruption of the blood-brain barrier (BBB) underlies the development of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis. Environmental factors, such as Bordetella pertussis, are thought to sensitize central endothelium to biogenic amines like histamine, thereby leading to increased BBB permeabi...
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.1008816107
更新日期:2010-11-02 00:00:00
abstract::Protein carboxymethylase, an enzyme capable of methylating proteins and polypeptides, was purified from bovine pituitary. The anterior pituitary hormones, luteinizing hormone, follicle-stimulating hormone, adrenocorticotropic hormone, growth hormone, thyroid-stimulating hormone, and prolactin, were found to be substra...
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.71.5.1701
更新日期:1974-05-01 00:00:00
abstract::Most variation in behavior has a genetic basis, but the processes determining the level of diversity at behavioral loci are largely unknown for natural populations. Expression of arginine vasopressin receptor 1a (Avpr1a) and oxytocin receptor (Oxtr) in specific regions of the brain regulates diverse social and reprodu...
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.1621228114
更新日期:2017-04-04 00:00:00
abstract::We recently reported that CD3- natural killer (NK) cells express the zeta chain of the T-cell receptor complex (zeta NK) in association with higher molecular weight structures whose expression differs between individual NK cell clones. Because NK cell cytolytic activity is known to be triggered by perturbation of 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.87.6.2274
更新日期:1990-03-01 00:00:00