Abstract:
:The synthesis of a photosensitive blocking group for the carboxyl function of neurotransmitters, in this case glycine, is reported. The compound, 2-methoxy-5-nitrophenyl glycine ester (caged glycine), is photolyzed by a laser pulse at 308 or 337 nm within 3 microseconds and with a product quantum yield of 0.2. The compound is hydrolyzed in water with a time constant tau of 6.1 min at pH 7.1 and 3 hr at pH 4.0. Mouse cerebral cortical neurons containing glycine receptors were used in biological assays. A cell-flow device, in which solutions of caged glycine at pH 4.0 were mixed with buffer to give a final pH of 7.1, was used to equilibrate the compound with receptors on the cell surface. Neither the caged compound nor the 2-methoxy-5-nitrophenol photolysis product affected the glycine receptors or modified their response to glycine. When cells equilibrated with caged glycine are irradiated by a laser pulse at 337 nm, glycine receptor channels are opened, as detected in whole-cell current recordings. The approach described may be used in the synthesis and characterization of photolabile precursors of neurotransmitters and other compounds that contain carboxyl groups and for kinetic investigations of neurotransmitter receptors in central nervous system cells in the microsecond time domain.
journal_name
Proc Natl Acad Sci U S Aauthors
Ramesh D,Wieboldt R,Niu L,Carpenter BK,Hess GPdoi
10.1073/pnas.90.23.11074subject
Has Abstractpub_date
1993-12-01 00:00:00pages
11074-8issue
23eissn
0027-8424issn
1091-6490journal_volume
90pub_type
杂志文章abstract::An enzymatic activity, having the properties expected of a B-specific host-controlled modification enzyme, has been purified from an extract of Escherichia coli strain B. This activity renders the unmodified replicative form of phage fd resistant to B-specific restriction and is only present in strains carrying intact...
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.63.2.556
更新日期:1969-06-01 00:00:00
abstract::Animal epithelial tissue becomes reproducibly colonized by specific environmental bacteria. The bacteria (microbiota) perform critical functions for the host's tissue development, immune system development, and nutrition; yet the processes by which bacterial diversity in the environment is selected to assemble the cor...
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.1415957111
更新日期:2014-12-02 00:00:00
abstract::Outer membrane protein (OMP) biogenesis is critical to bacterial physiology because the cellular envelope is vital to bacterial pathogenesis and antibiotic resistance. The process of OMP biogenesis has been studied in vivo, and each of its components has been studied in isolation in vitro. This work integrates paramet...
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.1601002113
更新日期:2016-08-16 00:00:00
abstract::Integrated hepatitis B virus (HBV) DNA is almost invariably found in hepatocellular carcinomas (HCC) which develop in HBV carriers. Integrated HBV DNAs from two single-integration HCCs (C3 and C4) have been cloned, and the cellular integration sites have been analyzed. Integrated HBV DNA of C3 is present in chromosome...
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.83.21.8338
更新日期:1986-11-01 00:00:00
abstract::Microtubules (MTs) are hollow cytoskeletal filaments assembled from αβ-tubulin heterodimers. Tau, an unstructured protein found in neuronal axons, binds to MTs and regulates their dynamics. Aberrant Tau behavior is associated with neurodegenerative dementias, including Alzheimer's. Here, we report on a direct force me...
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.1513172112
更新日期:2015-11-24 00:00:00
abstract::Habituation is a form of simple memory that suppresses neural activity in response to repeated, neutral stimuli. This process is critical in helping organisms guide attention toward the most salient and novel features in the environment. Here, we follow known circuit mechanisms in the fruit fly olfactory system to der...
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.1915252117
更新日期:2020-06-02 00:00:00
abstract::Assessments of the importance of different routes of HIV-1 (HIV) transmission are vital for prioritization of control efforts. Lack of consistent direct data and large uncertainty in the risk of HIV transmission from HIV-contaminated injections has made quantifying the proportion of transmission caused by contaminated...
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.0610435104
更新日期:2007-06-05 00:00:00
abstract::In the cell, proteins are synthesized from N to C terminus and begin to fold during translation. Cotranslational folding mechanisms are therefore linked to elongation rate, which varies as a function of synonymous codon usage. However, synonymous codon substitutions can affect many distinct cellular processes, which h...
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.1907126117
更新日期:2020-02-18 00:00:00
abstract::Oligodeoxyribonucleotides covalently linked to an intercalating agent via a polymethylene linker were synthesized. Oligothymidylates attached to an acridine dye (Acr) through the 3'-phosphate group [(Tp)n(CH2) mAcr ] specifically interact with the complementary sequence. The interaction is strongly stabilized by 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.81.11.3297
更新日期:1984-06-01 00:00:00
abstract::The 3' flanking region of the apolipoprotein B (apoB) gene contains a hypervariable region consisting of a variable number of tandemly repeated short A + T-rich DNA sequences (VNTRs). We present a general method that utilizes the polymerase chain reaction to rapidly and accurately type this and other VNTR loci. We use...
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.86.1.212
更新日期:1989-01-01 00:00:00
abstract::The determination of macromolecular structures requires weighting of experimental evidence relative to prior physical information. Although it can critically affect the quality of the calculated structures, experimental data are routinely weighted on an empirical basis. At present, cross-validation is the most rigorou...
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.0506412103
更新日期:2006-02-07 00:00:00
abstract::GB virus B (GBV-B), which infects tamarins, is the virus most closely related to hepatitis C virus (HCV). HCV has a protein (p7) that is believed to form an ion channel. It is critical for viability. In vitro studies suggest that GBV-B has an analogous but larger protein (p13). We found that substitutions of the -1 an...
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.0511297103
更新日期:2006-02-28 00:00:00
abstract::Whereas amyloid-β (Aβ) accumulates in the brain of normal animals dosed with low levels of copper (Cu), the mechanism is not completely known. Cu could contribute to Aβ accumulation by altering its clearance and/or its production. Because Cu homeostasis is altered in transgenic mice overexpressing Aβ precursor protein...
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.1302212110
更新日期:2013-09-03 00:00:00
abstract::By using an indirect immunofluorescence technique, the distribution of poly(ADP-ribose) synthesis in human blood cells was investigated. The antibody used was reactive with poly(ADP-ribose) larger than trimers. The specific immunofluorescence of poly(ADP-ribose) synthesized in situ from NAD+ was observed in nuclei 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.77.6.3682
更新日期:1980-06-01 00:00:00
abstract::Recent reports on the dystrophic mouse mutant suggest that the prominent extracellular matrix component of peripheral nerve tissues plays an important role in peripheral nerve development. We have examined the disposition of two prominent extracellular matrix components, fibronectin and laminin, both in mature periphe...
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.80.12.3850
更新日期:1983-06-01 00:00:00
abstract::The coexistence of two phylogenetically distinct symbiont species within a single cell, a condition not previously known in any metazoan, is demonstrated in the gills of a Mid-Atlantic Ridge hydrothermal vent mussel (family Mytilidae). Large and small symbiont morphotypes within the gill bacteriocytes are shown to be ...
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.92.21.9598
更新日期:1995-10-10 00:00:00
abstract::Several next-generation (universal) influenza vaccines and broadly neutralizing antibodies (bNAbs) are in clinical development. Some of these mediate inhibitions of virus replication at the postentry stage or use Fc-dependent mechanisms. Nonneutralizing antibodies have the potential to mediate enhancement of viral inf...
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.1821317116
更新日期:2019-07-23 00:00:00
abstract::This paper is a theoretical study of dynamic self assembly in a system of millimeter-sized magnetized disks floating at a liquid-air interface and spinning under the influence of a rotating magnetic field. Equations of motions are derived that account for the hydrodynamic and magnetic forces acting in the system. Nume...
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.062036699
更新日期:2002-04-02 00:00:00
abstract::alpha-Trichosanthin, a eukaryotic ribosome-inactivating protein from Trichosanthes kirilowii, inhibits the replication of the human immunodeficiency virus (HIV) in vitro. The alpha-trichosanthin gene was placed under the transcriptional control of a tobamovirus subgenomic promoter in a plant RNA viral vector. Two week...
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.90.2.427
更新日期:1993-01-15 00:00:00
abstract::Nontypeable Hemophilus influenzae (NTHi) is an important human pathogen in both children and adults. In children, it causes otitis media, the most common childhood infection and the leading cause of conductive hearing loss in the United States. In adults, it causes lower respiratory tract infections in the setting 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.151236098
更新日期:2001-07-17 00:00:00
abstract::The 8;21 translocation is one of the most common specific rearrangements in acute myelogenous leukemia. We have identified markers (D21S65 and a Not I boundary clone, Not-42, referred to as probe B) flanking the chromosome 21 translocation breakpoint (21q22.3) that demonstrate physical linkage in normal genomic DNA, b...
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.88.11.4882
更新日期:1991-06-01 00:00:00
abstract::A Mr 35,000 calmodulin-binding protein, which also possesses the ability to interact with a number of cytoskeletal elements, was purified from bovine synaptosomal membranes, using hydroxylapatite and phosphocellulose column chromatography. We call this protein "cytosynalin," which is derived from a combination 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.84.7.1916
更新日期:1987-04-01 00:00:00
abstract::Structure and function of p185neu receptor tyrosine kinase were found to be regulated in a cell cycle-dependent manner. In M phase, p185neu is hyperphosphorylated at serine and/or threonine residues. The phosphotyrosine [Tyr(P)] content of p185neu is at its highest level in G0/G1 phase, decreases through S and G2 phas...
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.92.4.1092
更新日期:1995-02-14 00:00:00
abstract::Previous studies have shown changes in membrane properties of neurons in rat deep cerebellar nuclei (DCN) as a function of development, but due to technical difficulties in obtaining viable DCN slices from adult animals, it remains unclear whether there are learning-related alterations in the membrane properties of DC...
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.1808539115
更新日期:2018-10-02 00:00:00
abstract::Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a ubiquitous mechanism that generates transcriptomic diversity. This process is particularly important for proper neuronal function; however, little is known about how RNA editing is dynamically regulated between the many functionally distinct ne...
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.1811768116
更新日期:2019-02-05 00:00:00
abstract::Many cell surface receptors are multimeric proteins, composed of several structural domains, some involved in ligand recognition, whereas others are responsible for signal transduction. In most cases, the mechanism of how ligand interaction in the extracellular domains leads to the activation of effector domains remai...
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.1107775108
更新日期:2011-09-13 00:00:00
abstract::Listeriolysin O (LLO) is a cholesterol-dependent cytolysin that is an essential virulence factor of Listeria monocytogenes. LLO pore-forming activity is pH-dependent; it is active at acidic pH (<6), but not at neutral pH. In contrast to other pH-dependent toxins, we have determined that LLO pore-forming activity is 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.0500558102
更新日期:2005-08-30 00:00:00
abstract::Agrobacterium tumefaciens transfers the T-DNA portion of its Ti plasmid to the nuclear genome of plant cells. Upon cocultivation of A. tumefaciens strain A348 with regenerating tobacco leaf protoplasts, restriction endonuclease fragments of the T-DNA were generated that are consistent with double-stranded cleavage 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.84.7.1881
更新日期:1987-04-01 00:00:00
abstract::In the coming century, anthropogenic climate change will threaten the persistence of restricted endemic species, complicating conservation planning. Although most efforts to quantify potential shifts in species' ranges use global climate model (GCM) output, regional climate model (RCM) output may be better suited to 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.0501427102
更新日期:2005-11-08 00:00:00
abstract::Cactus, a Drosophila homologue of I kappa B, binds to and inhibits Dorsal, a homologue of the p50 and p65 components of NF-kappa B. We describe experiments in yeast with various Dorsal and Cactus derivatives showing that Cactus blocks the DNA binding and nuclear localization functions of Dorsal. In contrast, Dorsal'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.92.22.10242
更新日期:1995-10-24 00:00:00