Abstract:
:Isolated developing plastids from greening cucumber cotyledons or from photoperiodically grown pea seedlings incorporated (14)C-labeled 5-aminolevulinic acid (ALA) into chlorophyll (Chl). Incorporation was light dependent, enhanced by S-adenosylmethionine, and linear for 1 hr. The in vitro rate of Chl synthesis from ALA was comparable to the in vivo rate of Chl accumulation. Levulinic acid and dioxoheptanoic acid strongly inhibited Chl synthesis but not plastid protein synthesis. Neither chloramphenicol nor spectinomycin affected Chl synthesis, although protein synthesis was strongly inhibited. Components of thylakoid membranes from plastids incubated with [(14)C]ALA were resolved by electrophoresis and then subjected to autoradiography. This work showed that (i) newly synthesized Chl was assembled into Chl-protein complexes and (ii) the inhibition of protein synthesis during the incubation did not alter the labeling pattern. Thus, there was no observable short-term coregulation between Chl synthesis (from ALA) and the synthesis of membrane proteins in isolated plastids.
journal_name
Proc Natl Acad Sci U S Aauthors
Bhaya D,Castelfranco PAdoi
10.1073/pnas.82.16.5370subject
Has Abstractpub_date
1985-08-01 00:00:00pages
5370-4issue
16eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::For centuries ecologists have studied how the diversity and functional traits of plant and animal communities vary across biomes. In contrast, we have only just begun exploring similar questions for soil microbial communities despite soil microbes being the dominant engines of biogeochemical cycles and a major pool 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.1215210110
更新日期:2012-12-26 00:00:00
abstract::Ion channels in excitable cells function in macromolecular complexes in which auxiliary proteins modulate the biophysical properties of the pore-forming subunits. Hyperpolarization-activated, cyclic nucleotide-sensitive HCN4 channels are critical determinants of membrane excitability in cells throughout the body, incl...
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.2006238117
更新日期:2020-07-28 00:00:00
abstract::Starting with assignments of proton nuclear magnetic resonance previously made for oxytocin in deuterated dimethylsulfoxide at 220 MHz, we have assigned resonances for the mammalian antidiuretic hormone, lysine vasopressin. The results demonstrate that spectral assignments of neurohypophyseal hormones and their congen...
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.69.7.1920
更新日期:1972-07-01 00:00:00
abstract::A temperature-sensitive (ts) mutant, GA 907/7, was isolated after mutagen treatment of avian myeloblastosis virus. When bone marrow cells or secondary yolk sac macrophages were infected with GA 907/7, the expression of transformation was greatly reduced at 41 degrees C. The results of temperature-shift experiments sug...
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.80.5.1421
更新日期:1983-03-01 00:00:00
abstract::A cDNA containing the full coding region of human cytochrome b5 was inserted into a vaccinia virus cDNA expression vector. Infection of human thymidine kinase-minus (TK-) 143 cells in culture with this recombinant virus resulted in production of 0.3 nmol of cytochrome b5 per mg of cell lysate protein. The expressed cy...
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.87.14.5425
更新日期:1990-07-01 00:00:00
abstract::U2 snRNP auxiliary factor 65 kDa (U2AF(65)) is a general splicing factor that contacts polypyrimidine (Py) tract and promotes prespliceosome assembly. In this report, we show that U2AF(65) stimulates alternative exon skipping in spinal muscular atrophy (SMA)-related survival motor neuron (SMN) pre-mRNA. A stronger 5' ...
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.1500639112
更新日期:2015-08-11 00:00:00
abstract::High ambient ozone (O3) concentrations are a widespread and persistent problem globally. Although studies have documented the role of forests in removing O3 and one of its precursors, nitrogen dioxide (NO2), the cost effectiveness of using peri-urban reforestation for O3 abatement purposes has not been examined. We 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.1409785111
更新日期:2014-10-07 00:00:00
abstract::Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of all aquatic food chains by fixing carbon and nitrogen into cellular biomass. The single most important nutrient for photosynthesis and growth is nitrate, which is severely limiting in many aquatic environment...
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.0602517103
更新日期:2006-06-27 00:00:00
abstract::Supernumerary B chromosomes are optional additions to the basic set of A chromosomes, and occur in all eukaryotic groups. They differ from the basic complement in morphology, pairing behavior, and inheritance and are not required for normal growth and development. The current view is that B chromosomes are parasitic 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.1204237109
更新日期:2012-08-14 00:00:00
abstract::Chaperone oligomerization is often a key aspect of their function. Irrespective of whether chaperone oligomers act as reservoirs for active monomers or exhibit a chaperoning function themselves, understanding the mechanism of oligomerization will further our understanding of how chaperones maintain the proteome. Here,...
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.2020306117
更新日期:2020-12-01 00:00:00
abstract::The Belgrade (b) rat has an autosomal recessively inherited, microcytic, hypochromic anemia associated with abnormal reticulocyte iron uptake and gastrointestinal iron absorption. The b reticulocyte defect appears to be failure of iron transport out of endosomes within the transferrin cycle. Aspects of this phenotype ...
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.95.3.1148
更新日期:1998-02-03 00:00:00
abstract::Kampo formulations are traditional herbal medications used in China and Japan for many centuries to treat diarrheal diseases such as cholera. Our studies were undertaken to identify and verify by chemical synthesis the active components that inhibited cholera toxin (CT), the virulence factor secreted by Vibrio cholera...
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.052709499
更新日期:2002-03-05 00:00:00
abstract::Eukaryotic mRNA degradation proceeds through two main pathways, both involving mRNA cap breakdown. In the 3'-5' mRNA decay pathway, mRNA body degradation generates free m7GpppN that is hydrolyzed by DcpS generating m7GMP. In the 5'-3' pathway, the recently identified human Dcp2 decapping enzyme cleaves the cap of dead...
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.1635192100
更新日期:2003-10-14 00:00:00
abstract::In classical knot theory and the theory of quantum invariants substantial effort was directed toward the search for unknotting moves on links. We solve, in this article, several classical problems concerning unknotting moves. Our approach uses a concept, Burnside groups of links, that establishes an unexpected relatio...
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.0406098101
更新日期:2004-12-14 00:00:00
abstract::RNA-directed DNA polymerase (reverse transcriptase) from leukocytes of individual leukemic patients can be grouped by velocity gradient analyses into two distinct classes, a low-molecular-weight (LMW) class of approximately 70,000 and a high-molecular-weight (HMW) class of 130,000 to 140,000. The reverse transcriptase...
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.72.3.1194
更新日期:1975-03-01 00:00:00
abstract::We demonstrate that poly(dA-dT) can adopt two conformations in solution, with the relative proportions dependent on the nature and concentration of the counter ion and cationic ligands. The synthetic DNA exhibits a dinucleotide repeat conformation on addition of CsF and Me4NCl at molar concentrations, with the NMR spe...
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.78.7.4063
更新日期:1981-07-01 00:00:00
abstract::In a study of juvenile hormone-regulated gene expression, we isolated an anonymous cDNA representing a message that was strongly suppressed by juvenile hormone in the fat body of the cockroach Blaberus discoidalis. The protein deduced from the cDNA sequence showed compelling resemblance in sequence to the transferrins...
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.90.4.1320
更新日期:1993-02-15 00:00:00
abstract::Influenza viruses contain segmented, negative-strand RNA genomes. Genome segmentation facilitates reassortment between different influenza virus strains infecting the same cell. This phenomenon results in the rapid exchange of RNA segments. In this study, we have developed a method to prevent the free reassortment 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.0908897106
更新日期:2009-09-15 00:00:00
abstract::The dynamics of excited-state double proton transfer of model DNA base pairs, 7-azaindole dimers, is reported using femtosecond fluorescence spectroscopy. To elucidate the nature of the transfer in the condensed phase, here we examine variation of solvent polarity and viscosity, solute concentration, and isotopic frac...
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.0702944104
更新日期:2007-05-22 00:00:00
abstract::Seed dormancy is a trait of considerable adaptive significance because it maximizes seedling survival by preventing premature germination under unfavorable conditions. Understanding how seeds break dormancy and initiate growth is also of great agricultural and biotechnological interest. Abscisic acid (ABA) plays prima...
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.081594298
更新日期:2001-04-10 00:00:00
abstract::Studies in mice indicate that the gut microbiota promotes energy harvest and storage from components of the diet when these components are plentiful. Here we examine how the microbiota shapes host metabolic and physiologic adaptations to periods of nutrient deprivation. Germ-free (GF) mice and mice who had received a ...
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.0902366106
更新日期:2009-07-07 00:00:00
abstract::Artificially aminoacylated suppressor tRNAs were used to introduce photoreactive amino acids into model mitochondrial precursor proteins to probe the environment along the protein import pathway. Amino acids with benzophenone side chains of various lengths [DL-2-amino-3-(p-benzoylphenyl)propanoic acid (1) and DL-2-ami...
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.94.2.485
更新日期:1997-01-21 00:00:00
abstract::Biological diversity reflects an underlying molecular diversity. The molecules found in nature may be regarded as solutions to challenges that have been confronted and overcome during molecular evolution. As our understanding of these solutions deepens, the efficiency with which we can discover and/or design new treat...
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.92.1.75
更新日期:1995-01-03 00:00:00
abstract::A close correlation was observed between intracellular Ca2+ pool depletion and refilling and the onset of DNA synthesis and proliferation of DDT1MF-2 smooth muscle cells. The intracellular Ca2+ pump inhibitors 2,5-di-tert-butyl-hydroquinone (DBHQ) and thapsigargin (TG) specifically emptied identical inositol 1,4,5-tri...
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.90.11.4986
更新日期:1993-06-01 00:00:00
abstract::In skeletal muscle, transcription of the gene encoding the mouse type Ialpha (RIalpha) subunit of the cAMP-dependent protein kinase is initiated from the alternative noncoding first exons 1a and 1b. Here, we report that activity of the promoter upstream of exon 1a (Pa) depends on two adjacent E boxes (E1 and E2) in NI...
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.081393598
更新日期:2001-04-24 00:00:00
abstract::Geckos can run rapidly on walls and ceilings, requiring high friction forces (on walls) and adhesion forces (on ceilings), with typical step intervals of approximately 20 ms. The rapid switching between gecko foot attachment and detachment is analyzed theoretically based on a tape model that incorporates the adhesion ...
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.0608841103
更新日期:2006-12-19 00:00:00
abstract::Arabidopsis thaliana endosperm, a transient tissue that nourishes the embryo, exhibits extensive localized DNA demethylation on maternally inherited chromosomes. Demethylation mediates parent-of-origin-specific (imprinted) gene expression but is apparently unnecessary for the extensive accumulation of maternally biase...
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.1306164110
更新日期:2013-05-07 00:00:00
abstract::We have used (13C)-1H NMR spectroscopy at 360.13 MHz to resolve the 13C coupled proton resonance of glutamate and lactate in the rat brain in vivo. The time required for the 13C fractional enrichment of the 4-CH2 position of brain glutamate to reach isotopic steady state was determined during a continuous infusion 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.82.6.1633
更新日期:1985-03-01 00:00:00
abstract::Developmental constraint is indicated when one finds that similar genetic mechanisms are responsible for independent origins of the same derived phenotype. We studied three independent origins of rosette flowering within the mustard family and attempted to evaluate the extent to which the same mechanisms were involved...
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.0401824101
更新日期:2004-04-27 00:00:00
abstract::Agrobacterium tumefaciens causes crown gall tumors on various plants by delivering transferred DNA (T-DNA) and virulence proteins into host plant cells. Under laboratory conditions, the bacterium is widely used as a vector to genetically modify a wide range of organisms, including plants, yeasts, fungi, and algae. 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.1612098114
更新日期:2017-03-14 00:00:00