Abstract:
:Fossil glycoproteins of the soluble organic matrix are present in an 80-million-year-old mollusk shell from the Late Cretaceous Period. Discrete molecular weight components, as determined by gel electrophoresis, are preserved. The fossil organic matrix was compared with the organic matrix of a living representative species of the same superfamily. A particular repeating amino acid sequence, found in contemporary mollusk shell proteins, was identified in the fossil glycoproteins. The ultrastructure, mineralogy, and chemistry of the inorganic components of the fossil and contemporary shells provide information on the state of preservation of the fossil. The use of fossil shell proteins to further our understanding of molecular evolution is discussed.
journal_name
Proc Natl Acad Sci U S Aauthors
Weiner S,Lowenstam HA,Hood Ldoi
10.1073/pnas.73.8.2541subject
Has Abstractpub_date
1976-08-01 00:00:00pages
2541-5issue
8eissn
0027-8424issn
1091-6490journal_volume
73pub_type
历史文章,杂志文章abstract::The p53 tumor suppressor protein and the MDM2 oncoprotein form a feedback-control loop that up-regulates cellular MDM2 production, blocks p53 activity, and promotes p53 decay. tsg101 was discovered as a gene whose deficiency results in neoplastic transformation of NIH 3T3 cells and the ability to generate metastatic 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.98.4.1619
更新日期:2001-02-13 00:00:00
abstract::cDNAs made from polyadenylylated RNAs of the mouse lens were cloned by the G.C tailing procedure in the bacterial plasmid pBR322. Four recombinant DNAs containing gamma-crystallin sequences were identified by hybrid selection and translation. Sequence analysis of the in vivo-labeled gamma-crystallin polypeptides that ...
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.79.9.2783
更新日期:1982-05-01 00:00:00
abstract::Neurogenesis has recently been observed in the adult human brain, suggesting the possibility of endogenous neural repair. However, the augmentation of neurogenesis in the adult human brain in response to neuronal cell loss has not been demonstrated. This study was undertaken to investigate whether neurogenesis occurs ...
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.1532244100
更新日期:2003-07-22 00:00:00
abstract::Monoclonal antibodies provide an attractive alternative to small-molecule therapies for a wide range of diseases. Given the importance of G protein-coupled receptors (GPCRs) as pharmaceutical targets, there has been an immense interest in developing therapeutic monoclonal antibodies that act on GPCRs. Here we present ...
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.1700891114
更新日期:2017-08-01 00:00:00
abstract::The Schiff base adducts of glyceraldehyde with hemoglobin undergo Amadori rearrangement to form stable ketoamine structures; this reaction is similar to the nonenzymic glucosylation of proteins. In the present studies the analogous rearrangement of the Schiff base adducts of glycolaldehyde with proteins has been demon...
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.80.12.3590
更新日期:1983-06-01 00:00:00
abstract::Although the p53 network has been intensively studied, genetic analyses long hinted at the existence of components that remained elusive. Recent studies have shown regulation of p53 at the mRNA level mediated via both the 5' and the 3' untranslated regions and affecting the stability and translation efficiency 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.1212533110
更新日期:2013-02-26 00:00:00
abstract::Mutator activity associated with the common male recombination (MR) chromosomes in Drosophila melanogaster appears to be suppressed in natural populations. Crosses between geographically separated populations, however, lead to the release of mutator activity as measured by a significant increase in visible mutations. ...
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.77.2.1059
更新日期:1980-02-01 00:00:00
abstract::The uncatalyzed reactions of O(2) (S = 1) with organic substrates (S = 0) are thermodynamically favorable but kinetically slow because they are spin-forbidden and the one-electron reduction potential of O(2) is unfavorable. In nature, many of these important O(2) reactions are catalyzed by metalloenzymes. In the case ...
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.0704191104
更新日期:2007-11-20 00:00:00
abstract::The notion of stability of a local ring arises naturally in investigating completed moduli spaces via geometric invariant theory. A scheme corresponding to a boundary point of a moduli space of nonsingular varieties cannot have unstable singular points. This paper reports some results concerning the stability of surfa...
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.75.9.4085
更新日期:1978-09-01 00:00:00
abstract::Natural transformation (i.e., the uptake of DNA and its stable integration in the chromosome) is a major mechanism of horizontal gene transfer in bacteria. Although the vast majority of bacterial genomes carry the genes involved in natural transformation, close relatives of naturally transformable species often appear...
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.1909374116
更新日期:2019-09-10 00:00:00
abstract::Cranial neural crest cells (crNCCs) migrate from the neural tube to the pharyngeal arches (PAs) of the developing embryo and, subsequently, differentiate into bone and connective tissue to form the mandible. Within the PAs, crNCCs respond to local signaling cues to partition into the proximo-distally oriented subdomai...
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.1603930113
更新日期:2016-07-05 00:00:00
abstract::Clonal expansion of premalignant lesions is an important step in the progression to cancer. This process is commonly considered to be a consequence of sustaining a proliferative mutation. Here, we investigate whether the growth trajectory of clones can be better described by a model in which clone growth does not depe...
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.0802211105
更新日期:2008-09-30 00:00:00
abstract::The rate of leucine incorporation into a specific estrogen-induced protein of immature rat isolated by gel electrophoresis declines rapidly between 2-4 hr after estrogen stimulation in vivo followed by incubation in vitro. Actinomycin D present during the in vitro phase prevents this decline, and elicits a "superinduc...
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.70.1.18
更新日期:1973-01-01 00:00:00
abstract::Williams-Beuren syndrome (also known as Williams syndrome) is caused by a deletion of a 1.55- to 1.84-megabase region from chromosome band 7q11.23. GTF2IRD1 and GTF2I, located within this critical region, encode proteins of the TFII-I family with multiple helix-loop-helix domains known as I repeats. In the present wor...
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.0404150101
更新日期:2004-07-27 00:00:00
abstract::Liquid RNA.DNA hybridization with separated strands of adenovirus type 2 DNA revealed that late nuclear RNA can hybridize to about 85% of the 1-strand and 10-15% of the h-strand, whereas late cytoplasmic RNA hybridizes to 65-70% and 25% of the l- and h-strand, respectively. With separated strands from the six EcoRI fr...
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.71.12.4887
更新日期:1974-12-01 00:00:00
abstract::In the antennal lobe of Drosophila, information about odors is transferred from olfactory receptor neurons (ORNs) to projection neurons (PNs), which then send axons to neurons in the lateral horn of the protocerebrum (LHNs) and to Kenyon cells (KCs) in the mushroom body. The transformation from ORN to PN responses can...
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.1005635107
更新日期:2010-06-08 00:00:00
abstract::An explosion of new information linking activation of cell surface signal initiators to changes in gene expression has recently emerged. The focus of much of this information has centered around the agonist-dependent activation of the mitogen-activated protein (MAP) kinases. Although this intracellular signal transduc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.90.13.5889
更新日期:1993-07-01 00:00:00
abstract::A mathematical analysis of the formation of hemolytic plaques in agar is presented. The results can be used to calculate the rate constant for antigen-antibody association and the distribution of antibody secretion rates. The limitations of the treatment and estimates of the expected errors involved are briefly discus...
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.71.1.16
更新日期:1974-01-01 00:00:00
abstract::The somatostatin receptor subtype 2 (sst2) behaves as a tumor suppressor when expressed and stimulated by its ligand somatostatin in pancreatic cancer. We reveal a mechanism underlying oncosuppressive action of sst2, whereby this inhibitory receptor upregulates the expression of the secreted angioinhibitory factor thr...
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.0908674106
更新日期:2009-10-20 00:00:00
abstract::It is shown that polyphosphates are not generated in significant amounts in the phosphoglycerate kinase reaction; polyphosphate is more effective than ATP in the formation of glucose 6-P by glucokinase, but the rate with ATP may be adequate to meet the requirements of glucose metabolism; PPi is far more effective than...
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.82.2.312
更新日期:1985-01-01 00:00:00
abstract::The ubiquitin ligase Siah2 has been shown to regulate prolyl hydroxylase 3 (PHD3) stability with concomitant effect on HIF-1alpha availability. Because HIF-1alpha is implicated in tumorigenesis and metastasis, we used SW1 mouse melanoma cells, which develop primary tumors with a propensity to metastasize, in a syngene...
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.0804063105
更新日期:2008-10-28 00:00:00
abstract::Human IL-10 (hIL-10) modulates critical immune and inflammatory responses by way of interactions with its high- (IL-10R1) and low-affinity (IL-10R2) cell surface receptors. Human cytomegalovirus exploits the IL-10 signaling pathway by expressing a functional viral IL-10 homolog (cmvIL-10), which shares only 27% sequen...
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.152147499
更新日期:2002-07-09 00:00:00
abstract::The biosynthesis and endocrine regulation of sex pheromone production in the female German cockroach (Blattella germanica) were determined. Radio-TLC and radio-GLC were used to demonstrate the metabolism of 3,11-dimethylnonacosane, a major cuticular lipid component, to the corresponding alkan-2-ol and methyl ketone. [...
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.89.13.6050
更新日期:1992-07-01 00:00:00
abstract::Drug discovery in psychiatry has been limited to chemical modifications of compounds originally discovered serendipitously. Therefore, more mechanism-oriented strategies of drug discovery for mental disorders are awaited. Schizophrenia is a devastating mental disorder with synaptic disconnectivity involved in its path...
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.1321109111
更新日期:2014-04-29 00:00:00
abstract::Stress-induced structural remodeling in the adult hippocampus, involving debranching and shortening of dendrites and suppression of neurogenesis, provides a cellular basis for understanding the impairment of neural plasticity in the human hippocampus in depressive illness. Accordingly, reversal of structural remodelin...
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.211427898
更新日期:2001-10-23 00:00:00
abstract::Loss of function of CDKN2A/B, also known as INK4/ARF [encoding p16INK4A, p15INK4B, and p14ARF (mouse p19Arf)], confers susceptibility to cancers, whereas its up-regulation during organismal aging provokes cellular senescence and tissue degenerative disorders. To better understand the transcriptional regulation of p16 ...
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.1909720116
更新日期:2019-12-09 00:00:00
abstract::Injection of antisense oligonucleotides was used to investigate the function of c-mos in murine oocytes. Oocytes injected with antisense c-mos oligonucleotides completed the first meiotic division but failed to initiate meiosis II. Instead, loss of c-mos function led to chromosome decondensation, reformation of a nucl...
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.86.18.7038
更新日期:1989-09-01 00:00:00
abstract::Barttin is an accessory subunit of a subgroup of ClC-type chloride channels expressed in renal and inner ear epithelia. In this study, we examined the effects of barttin on two ClC-K channel isoforms, rat ClC-K1 and human ClC-Kb, using heterologous expression, patch clamping, confocal imaging, and flow cytometry. In 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.0601631103
更新日期:2006-07-25 00:00:00
abstract::Photoadaptation, the ability to attenuate a light response on prolonged light exposure while remaining sensitive to escalating changes in light intensity, is essential for organisms to decipher time information appropriately, yet the underlying molecular mechanisms are poorly understood. In Neurospora crassa, VIVID (V...
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.1011190107
更新日期:2010-09-21 00:00:00
abstract::The Arabidopsis thaliana AtHKT1 protein, a Na(+)/K(+) transporter, is capable of mediating inward Na(+) currents in Xenopus laevis oocytes and K(+) uptake in Escherichia coli. HKT1 proteins are members of a superfamily of K(+) transporters. These proteins have been proposed to contain eight transmembrane segments 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.101556598
更新日期:2001-05-22 00:00:00