Abstract:
:To investigate the chemical relationships between rat liver lysosomal and microsomal beta-D-glucuronidases (EC 3.2.1.31), which are essentially identical catalytically and in reactivity with antibody and similar in molecular weight, the two enzymes were isolated by procedures in which modifications of the proteins were avoided. The purified enzymes were found to differ in both sugar and amino acid compositions. The microsomal enzyme contained much more mannose and, in contrast to the lysosomal enzyme, contained sialic acid but no glucose. Moreover, although the amino acid compositions generally agreed closely, the microsomal enzyme contained much more serine and somewhat less arginine than the lysosomal form. These findings of specific differences in composition should have a bearing on the consideration of intracellular glycoprotein synthesis, translocation, and compartmentalization.
journal_name
Proc Natl Acad Sci U S Aauthors
Tulsiani DR,Six H,Touster Odoi
10.1073/pnas.75.7.3080subject
Has Abstractpub_date
1978-07-01 00:00:00pages
3080-4issue
7eissn
0027-8424issn
1091-6490journal_volume
75pub_type
杂志文章abstract::Muscarinic acetylcholine receptors (mAChR) in the embryonic chicken heart undergo agonist-induced internalization and a subsequent decrease in receptor number (downregulation). Cloning studies have identified two subtypes of mAChR expressed in the embryonic chicken heart, the cm2 and cm4 receptors. We report here 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.89.11.5035
更新日期:1992-06-01 00:00:00
abstract::We describe the partial purification of an endonuclease from calf thymus that nicks phage PM2 DNA irradiated with UV doses producing only a few pyrimidine dimers per molecule. It has much less activity on DNA that has been subjected to enzymatic photoreactivation after UV irradiation. The calf thymus endonuclease is d...
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.76.8.3746
更新日期:1979-08-01 00:00:00
abstract::We have previously shown that hepatitis B virus (HBV) replication is controlled by noncytolytic mechanisms that depend primarily on the effector functions of the CD8(+) T cell response, especially the production of IFN-gamma in the liver. The mechanisms that control the nuclear pool of viral covalently closed circular...
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.0308478100
更新日期:2004-02-17 00:00:00
abstract::The mammalian anx7 gene codes for a Ca(2+)-activated GTPase, which supports Ca(2+)/GTP-dependent secretion events and Ca(2+) channel activities in vitro and in vivo. To test whether anx7 might be involved in Ca(2+) signaling in secreting pancreatic beta cells, we knocked out the anx7 gene in the mouse and tested the 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.96.24.13783
更新日期:1999-11-23 00:00:00
abstract::Chromosome movement during mitosis is powered in part by energy released through the depolymerization of kinetochore microtubules (MTs). Strong but indirect evidence suggests the existence of a specialized coupling between kinetochores and MT plus ends that enables this transduction of chemical energy into mechanical ...
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.0501142102
更新日期:2005-03-22 00:00:00
abstract::Alzheimer's disease (AD) is characterized by a progressive dysfunction of central neurons. Recent experimental evidence indicates that in the cortex, in addition to the silencing of a fraction of neurons, other neurons are hyperactive in amyloid-β (Aβ) plaque-enriched regions. However, it has remained unknown what com...
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.1206171109
更新日期:2012-05-29 00:00:00
abstract::Visual awareness has been proposed to depend on recurrent processing in early visual cortex areas including the primary visual cortex (V1). Here, we address this hypothesis with high spatiotemporal resolution magnetoencephalographic recordings in subjects performing a substitution masking paradigm. Neural activity ref...
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.0801999105
更新日期:2008-06-24 00:00:00
abstract::Both mammals and birds use the interaural time difference (ITD) for localization of sound in the horizontal plane. They may localize either real or phantom sound sources, when the signal consists of a narrow frequency band. This ambiguity does not occur with broadband signals. A plot of impulse rates or amplitude of e...
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.97.22.11787
更新日期:2000-10-24 00:00:00
abstract::Most human cancers are aneuploid and have chromosomal instability, which contrasts to the inability of human cells to normally tolerate aneuploidy. Noting that aneuploidy in human breast cancer correlates with increased expression levels of the Mps1 checkpoint gene, we investigated whether these high levels of Mps1 co...
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.1007645108
更新日期:2011-03-29 00:00:00
abstract::We have found that three Escherichia coli heat shock proteins, DnaK (the hsp70 homolog), DnaJ, and GrpE, function in oriP1 DNA replication in vitro solely to activate DNA binding by the replication initiator protein RepA. Activation results from the conversion of P1 or P7 RepA dimers to monomers that bind with high af...
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.89.21.10345
更新日期:1992-11-01 00:00:00
abstract::A 90-kDa surface glycoprotein was previously isolated and shown to be required for infection by the "major" group of human rhinovirus (HRV) serotypes. In the present work, the amino acid sequence of the receptor protein was obtained from CNBr and tryptic peptides. Using degenerate oligonucleotides predicted from the p...
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.86.13.4907
更新日期:1989-07-01 00:00:00
abstract::Using a tissue culture system based on a nearly pure population of avian precartilage mesenchymal cells, we have found that ambient glucose levels as little as 50% lower, or 100% higher, than normally present in embryonic sera are deleterious to cartilage development, as measured by the accumulation of highly sulfated...
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.86.24.10113
更新日期:1989-12-01 00:00:00
abstract::The HIV envelope (Env) protein mediates entry into cells by binding CD4 and an appropriate coreceptor, which triggers structural changes in Env that lead to fusion between the viral and cellular membranes. The major HIV-1 coreceptors are the seven transmembrane domain chemokine receptors CCR5 and CXCR4. The type of co...
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.190274097
更新日期:2000-10-10 00:00:00
abstract::The migration of species across interfaces can crucially affect the performance of heterogeneous catalysts. A key concept in using bimetallic catalysts for hydrogenation is that the active metal supplies hydrogen atoms to the host metal, where selective hydrogenation can then occur. Herein, we demonstrate that, follow...
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.2010413117
更新日期:2020-09-15 00:00:00
abstract::Multiple biological processes involve the stretching of nucleic acids (NAs). Stretching forces induce local changes in the molecule structure, inhibiting or promoting the binding of proteins, which ultimately affects their functionality. Understanding how a force induces changes in the structure of NAs at the atomic l...
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.1705642114
更新日期:2017-07-03 00:00:00
abstract::Grasslands cover more than 20% of the Earth's terrestrial surface, and their rise to dominance is one of the most dramatic events of biome evolution in Earth history. Grasses possess two main photosynthetic pathways: the C(3) pathway that is typical of most plants and a specialized C(4) pathway that minimizes photores...
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.0909672107
更新日期:2010-02-09 00:00:00
abstract::Acidification of the extracellular milieu of malignant tumors is reported to increase the invasive behavior of cancer cells. In normal tissues, production of acid is catalyzed by carbonic anhydrases (CAs), some of which are known to be overexpressed in certain cancers. To investigate the functional role of CA activity...
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.040554897
更新日期:2000-02-29 00:00:00
abstract::Atmospheric models generally assume that aerosol particles are in equilibrium with the surrounding gas phase. However, recent observations that secondary organic aerosols can exist in a glassy state have highlighted the need to more fully understand the kinetic limitations that may control water partitioning in ambien...
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.1200691109
更新日期:2012-07-17 00:00:00
abstract::An understanding of the division of labor in different societies, and especially how it evolved in the human species, is fundamental to most analyses of social, political, and economic systems. The ability to reconstruct how labor was organized, however, especially in ancient societies that left behind few material re...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.1901367116
更新日期:2019-06-18 00:00:00
abstract::The distribution of enkephalin-like immunoreactivity within the avian retina was studied by immunofluorescence and immunoperoxidase techniques with antiserum to [Met5]enkephalin and [Leu5]enkephalin. Formaldehyde-fixed retinae were sectioned and incubated in antiserum to either [Met5]- or [Leu5]enkephalin. Specificity...
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.76.6.3010
更新日期:1979-06-01 00:00:00
abstract::The molecular mechanisms by which transcription is selectively activated and precisely controlled by signal transducer and activator of transcription (Stat) factors represent a central issue in cytokine-mediated cellular responses. Stat6 mediates responses to IL-4 and antagonizes Stat1 activated by IFN-gamma. We have ...
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.0506981103
更新日期:2006-03-14 00:00:00
abstract::Egg activation is the process by which a mature oocyte becomes capable of supporting embryo development. In vertebrates and echinoderms, activation is induced by fertilization. Molecules introduced into the egg by the sperm trigger progressive release of intracellular calcium stores in the oocyte. Calcium wave(s) spre...
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.1420589112
更新日期:2015-01-20 00:00:00
abstract::Metabolic engineering seeks to reprogram microbial cells to efficiently and sustainably produce value-added compounds. Since chemical production can be at odds with the cell's natural objectives, strategies have been developed to balance conflicting goals. For example, dynamic regulation modulates gene expression to f...
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.1911144116
更新日期:2019-12-17 00:00:00
abstract::Increased understanding of the precise molecular mechanisms involved in cell survival and cell death signaling pathways offers the promise of harnessing these molecules to eliminate cancer cells without damaging normal cells. Tyrosine kinase oncoproteins promote the genesis of leukemias through both increased cell pro...
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.1206551110
更新日期:2013-02-05 00:00:00
abstract::Stromal cell lines were established from canine long-term marrow cultures, cloned by limiting dilution, and maintained in stromal cell-conditioned medium. These cells grew adherent, maintained stable growth rate and morphology under standard conditions (in 20-30% conditioned medium; confluency, 70-90%), and supported ...
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.92.3.748
更新日期:1995-01-31 00:00:00
abstract::A double-stranded (ds) DNA which may be a replication intermediate was isolated from bean (Phaseolus vulgaris L. "Top Crop") leaves systemically infected with bean golden mosaic virus, a whitefly-transmitted plant virus with a genome of circular single-stranded (ss) DNA. The isolation method used phenol/chloroform ext...
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.78.7.4102
更新日期:1981-07-01 00:00:00
abstract::We demonstrate that the BC200 RNA gene, which encodes a neural small cytoplasmic RNA, is a member of the most prodigious family of interspersed repetitive DNA and that its product represents an example of a primate tissue-specific RNA polymerase III transcript. The BC200 RNA gene is an early monomeric member and one 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.90.24.11563
更新日期:1993-12-15 00:00:00
abstract::Although pain is a prevalent nonmotor symptom in Parkinson's disease (PD), it is undertreated, in part because of our limited understanding of the underlying mechanisms. Considering that the basal ganglia are implicated in pain sensation, and that their synaptic outputs are controlled by the subthalamic nucleus (STN),...
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.1916263117
更新日期:2020-05-05 00:00:00
abstract::Assembly of protein complexes is a key mechanism for achieving spatial and temporal coordination in processes involving many enzymes. Growth of rod-shaped bacteria is a well-studied example requiring such coordination; expansion of the cell wall is thought to involve coordination of the activity of synthetic enzymes 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.1313826111
更新日期:2014-03-25 00:00:00
abstract::N-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces neuropathological and clinical abnormalities in humans, monkeys, and mice that closely resemble idiopathic parkinsonism. N-Methyl-4-phenylpyridine (MPP+), a metabolite of MPTP formed by monoamine oxidase B, is accumulated into striatal and cerebral cortical ...
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.82.7.2173
更新日期:1985-04-01 00:00:00