Abstract:
:The total amount of noncoding sequences on chromosomes of contemporary organisms varies significantly from species to species. We propose a hypothesis for the origin of these noncoding sequences that assumes that (i) an approximately equal to 0.55-kilobase (kb)-long reading frame composed the primordial gene and (ii) a 20-kb-long single-stranded polynucleotide is the longest molecule (as a genome) that was polymerized at random and without a specific template in the primordial soup/cell. The statistical distribution of stop codons allows examination of the probability of generating reading frames of approximately equal to 0.55 kb in this primordial polynucleotide. This analysis reveals that with three stop codons, a run of at least 0.55-kb equivalent length of nonstop codons would occur in 4.6% of 20-kb-long polynucleotide molecules. We attempt to estimate the total amount of noncoding sequences that would be present on the chromosomes of contemporary species assuming that present-day chromosomes retain the prototype primordial genome structure. Theoretical estimates thus obtained for most eukaryotes do not differ significantly from those reported for these specific organisms, with only a few exceptions. Furthermore, analysis of possible stop-codon distributions suggests that life on earth would not exist, at least in its present form, had two or four stop codons been selected early in evolution.
journal_name
Proc Natl Acad Sci U S Aauthors
Naora H,Miyahara K,Curnow RNdoi
10.1073/pnas.84.17.6195subject
Has Abstractpub_date
1987-09-01 00:00:00pages
6195-9issue
17eissn
0027-8424issn
1091-6490journal_volume
84pub_type
杂志文章abstract::The number of x-irradiated mammalian cells surviving is markedly increased when the cells are incubated with an uncoupler of oxidative phosphorylation prior to or immediately after irradiation. This increase is greater in plateau-phase cells than in exponentially growing cells. The increase in survival is related to t...
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.77.5.2702
更新日期:1980-05-01 00:00:00
abstract::Voltage-gated sodium (Na(V)) and potassium (K(V)) channels are critical components of neuronal action potential generation and propagation. Here, we report that Na(V)β1 encoded by SCN1b, an integral subunit of Na(V) channels, coassembles with and modulates the biophysical properties of K(V)1 and K(V)7 channels, but no...
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.1209142109
更新日期:2012-11-06 00:00:00
abstract::Proteins with intrinsically disordered domains are implicated in a vast range of biological processes, especially in cell signaling and regulation. Having solved the quaternary structure of the folded domains in the tumor suppressor p53 by a multidisciplinary approach, we have now determined the average ensemble struc...
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.0801353105
更新日期:2008-04-15 00:00:00
abstract::An immunoglobulin light chain protein was isolated from the urine of an individual (BRE) with systemic amyloidosis. Complete amino acid sequence of the variable region of the light chain (VL) protein established it as a kappa I, which when compared with other kappa I amyloid associated proteins had unique residues, 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.92.21.9490
更新日期:1995-10-10 00:00:00
abstract::We demonstrate gene transfer into rat heart in vivo by the direct injection of plasmid DNA. Injection of gene constructs driven by retroviral and cellular promoters resulted in detectable levels of reporter gene activities. The cellular promoter and 5' flanking sequence (positions -613 to +32) were derived from the ra...
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.88.10.4138
更新日期:1991-05-15 00:00:00
abstract::Stem cells have been identified as essential for maintaining multiple organ systems, including the hematopoietic system. The distinct cell fates of self-renewal and differentiation of hematopoietic stem cells (HSCs) depend on cell division. Recently, several negative regulators of the cell cycle, such as the cyclin-de...
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.0603389103
更新日期:2006-06-13 00:00:00
abstract::A well-known indication that a nucleotide has bound to myosin is the enhancement of the fluorescence of a specific tryptophan in the "subfragment 1" segment of the protein. Empirically the effect has been enormously useful in myosin enzymology. But beyond an early suggestion that it arises from a purine-tryptophan cha...
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.90.14.6791
更新日期:1993-07-15 00:00:00
abstract::Transforming growth factor beta (TGF-beta) causes growth arrest in most cell types. TGF-beta induces hypophosphorylation of retinoblastoma susceptibility gene 1 product (RB), which sequesters E2F factors needed for progression into S phase of the cell cycle, thereby leading to cell cycle arrest at G1. It is possible, ...
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.94.10.4948
更新日期:1997-05-13 00:00:00
abstract::Titania, which exhibits superwetting under light illumination, has been widely used as an ideal material for environmental solution such as self-cleaning, water-air purification, and antifogging. There have been various studies to understand such superhydrophilic conversion. The origin of superwetting has not been cla...
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.1319001111
更新日期:2014-04-22 00:00:00
abstract::How pathogenic cluster of differentiation 4 (CD4) T cells in rheumatoid arthritis (RA) develop remains poorly understood. We used Nur77-a marker of T cell antigen receptor (TCR) signaling-to identify antigen-activated CD4 T cells in the SKG mouse model of autoimmune arthritis and in patients with RA. Using a fluoresce...
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.1904271116
更新日期:2019-09-10 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
abstract::A fundamental mystery of plant cell biology is the occurrence of "stromules," stroma-filled tubular extensions from plastids (such as chloroplasts) that are universally observed in plants but whose functions are, in effect, completely unknown. One prevalent hypothesis is that stromules exchange signals or metabolites ...
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.1511570112
更新日期:2015-08-11 00:00:00
abstract::The adaptations in the freshwater turtle that permit survival despite prolonged loss of mitochondrial ATP generation were investigated by comparing the bioenergetics of turtle brain slices with rat brain slices. Aerobic turtle brain shows no significant difference in basal levels of total ATP generation compared to ra...
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.76.8.3922
更新日期:1979-08-01 00:00:00
abstract::Stomatal pores are microscopic structures on the epidermis of leaves formed by 2 specialized guard cells that control the exchange of water vapor and CO(2) between plants and the atmosphere. Stomatal size (S) and density (D) determine maximum leaf diffusive (stomatal) conductance of CO(2) (g(c(max))) to sites of assim...
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.0904209106
更新日期:2009-06-23 00:00:00
abstract::There are two competing hypotheses for the origin of megaliths in Europe. The conventional view from the late 19th and early 20th centuries was of a single-source diffusion of megaliths in Europe from the Near East through the Mediterranean and along the Atlantic coast. Following early radiocarbon dating in the 1970s,...
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.1813268116
更新日期:2019-02-26 00:00:00
abstract::A method has been developed that enables us to identify intracellular degradation intermediates of fructose-bisphosphate aldolase B (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13). This method is based on the use of antibody against thoroughly denatured purified aldolase. This antibody ha...
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.82.18.6114
更新日期:1985-09-01 00:00:00
abstract::Tetherin/BST2 is a type-II membrane protein that inhibits the release of a range of enveloped viruses, including HIV-1. Here we report three crystal structures of human tetherin, including the full-length ectodomain, a triple cysteine mutant and an ectodomain truncation. These structures show that tetherin forms 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.1011485107
更新日期:2010-10-26 00:00:00
abstract::A search for potent toxins that inhibit neuronal calcium channels in Drosophila melanogaster has resulted in the identification of a presynaptic neurotoxin from the venom of the hunting spider Hololena curta. Using Drosophila neuromuscular junction as an assay, presynaptic inhibitory activity was purified using gel fi...
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.84.10.3506
更新日期:1987-05-01 00:00:00
abstract::Tregs are essential for maintaining peripheral tolerance, and thus targeting these cells may aid in the treatment of autoimmunity and cancer by enhancing or reducing suppressive functions, respectively. Before these cells can be harnessed for therapeutic purposes, it is necessary to understand how they maintain tolera...
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.1605849113
更新日期:2016-08-09 00:00:00
abstract::A long (20-30 micrometer), wide (3-5 micrometer) microbial-mat bacterium from the Ebro Delta (Tarragona, Spain) was grown in mixed culture and videographed live. Intracellular elemental sulfur globules and unique cell termini were observed in scanning-electron-microprobe and transmission-electron micrographs. A polar ...
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.96.20.11584
更新日期:1999-09-28 00:00:00
abstract::Direct conversion of carbon dioxide to multicarbon products remains as a grand challenge in electrochemical CO2 reduction. Various forms of oxidized copper have been demonstrated as electrocatalysts that still require large overpotentials. Here, we show that an ensemble of Cu nanoparticles (NPs) enables selective form...
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.1711493114
更新日期:2017-10-03 00:00:00
abstract::The T lineage repertoire is shaped by T cell receptor (TCR)-dependent positive and negative thymic selection processes. Using TCR-transgenic (N15tg) beta2-microglobulin-deficient (beta2m-/-) RAG-2(-/-) H-2(b) mice specific for the VSV8 (RGYVYQGL) octapeptide bound to Kb, we identified a single weak agonist peptide var...
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.95.17.10061
更新日期:1998-08-18 00:00:00
abstract::Circadian pacemaking requires the orderly synthesis, posttranslational modification, and degradation of clock proteins. In mammals, mutations in casein kinase 1 (CK1) epsilon or delta can alter the circadian period, but the particular functions of the WT isoforms within the pacemaker remain unclear. We selectively 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.1005101107
更新日期:2010-08-24 00:00:00
abstract::We have synthesized two sets of 15-base-long oligodeoxyribonucleotides corresponding to all possible coding sequences for a small portion of human beta 2-microglobulin. Labeled oligonucleotides were used as hybridization probes to screen bacterial clones containing cDNA sequences primed with oligo(dT) and inserted int...
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.78.11.6613
更新日期:1981-11-01 00:00:00
abstract::To investigate the contribution of interleukin-4 (IL-4) to airway inflammation in vivo and to explore directly its relationship to airway reactivity, we created transgenic mice in which the murine cDNA for IL-4 was regulated by the rat Clara cell 10 protein promoter. Expression was detected only in the lung and not 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.93.15.7821
更新日期:1996-07-23 00:00:00
abstract::Although(,) vascular remodeling is a hallmark of many chronic inflammatory disorders such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis, anti-vascular strategies to treat these conditions have received little attention to date. We investigated the anti-inflammatory activity of systemic blockade 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.0907550106
更新日期:2009-12-15 00:00:00
abstract::In enteric bacteria, the cellular response to oxidative stress is activated by oxidation of the iron-sulfur clusters in SoxR, which then induces transcription of soxS, turning on a battery of defense genes. Here we demonstrate both in vitro and in cells that activation of SoxR can occur in a DNA-mediated reaction 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.0906429106
更新日期:2009-08-11 00:00:00
abstract::Although soft devices (grippers, actuators, and elementary robots) are rapidly becoming an integral part of the broad field of robotics, autonomy for completely soft devices has only begun to be developed. Adaptation of conventional systems of control to soft devices requires hard valves and electronic controls. This ...
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.1820672116
更新日期:2019-04-16 00:00:00
abstract::Selection of mammalian cells in progressively increasing concentrations of methotrexate results in selective amplification of DNA sequences coding for dihydrofolate reductase (tetrahydrofolate dehydrogenase, 5,6,7,8-tetrahydrofolate:NADP+ oxidoreductase, EC 1.5.1.3). In some cell variants the amplified genes are stabl...
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.76.11.5669
更新日期:1979-11-01 00:00:00
abstract::Several inhibitors of gamma-glutamyl transpeptidase in vitro [L-serine plus borate, 6-diazo-5-oxo-L-norleucine, and L- and D-gamma-glutamyl-(o-carboxy)phenylhydrazide] are active in vivo, as indicated by their effect in decreasing the conversion of administered D-gamma-glutamyl-L-alpha-amino[(14)C]butyrate to respirat...
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.76.1.268
更新日期:1979-01-01 00:00:00