Abstract:
:Certain Escherichia coli mutants defective in phosphatidylglycerol biosynthesis accumulate two novel glycolipids, designated X and Y. Lipid X is a diacylglucosamine 1-phosphate bearing beta-hydroxymyristoyl groups at positions 2 and 3, and lipid Y has the same structure as X, except for the additional presence of a palmitoyl moiety on the N-linked beta-hydroxymyristate. We have examined the activities of X, Y, and several related compounds as activators of macrophages. Both X and Y induce morphological changes (spreading), prostaglandin E2 synthesis, and killing of tumor cells by mouse peritoneal macrophages in vitro, properties with which lipopolysaccharide and lipid A are also endowed. Both glycolipids have similar effects on the macrophage-like mouse cell line J774.1. Selective removal from lipid X of either the ester-linked beta-hydroxymyristate at position 3 or the phosphate at position 1 abolishes activity. Our results show that the monosaccharides X and Y retain some of the properties of intact lipopolysaccharide and lipid A with respect to macrophage activation. Because the structures of X and Y are defined, our findings should facilitate the elucidation of the molecular mechanism of macrophage activation by lipid A.
journal_name
Proc Natl Acad Sci U S Aauthors
Nishijima M,Amano F,Akamatsu Y,Akagawa K,Tokunaga T,Raetz CRdoi
10.1073/pnas.82.2.282subject
Has Abstractpub_date
1985-01-01 00:00:00pages
282-6issue
2eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::CDK7 is a cyclin-dependent kinase proposed to function in two essential cellular processes: transcription and cell cycle regulation. CDK7 is the kinase subunit of the general transcription factor TFIIH that phosphorylates the C-terminal domain (CTD) of RNA polymerase II, and has been shown to be broadly required for 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.082618399
更新日期:2002-04-16 00:00:00
abstract::One goal of regenerative medicine is to repair damaged tissue. This requires not only generating new cells of the proper phenotype, but also selecting for those that properly integrate into sites of injury. In our laboratory we are using a cell-migration-based in vivo selection system to generate antibodies that induc...
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.1719259115
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abstract::The development of cardiac hypertrophy is mediated, in part, by increase in NADPH oxidase activity and myocardial oxidative stress. The Rho GTPase, Rac, regulates NADPH oxidase activity through interaction with gp91(phox) and p67(phox) (in which "phox" is phagocyte oxidase). However, it is not known which Rac isoform ...
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.0510444103
更新日期:2006-05-09 00:00:00
abstract::If, because of trade-offs or similar considerations, components of fitness are negatively correlated in equilibrium populations, they may then exhibit no correlation with total fitness. Lack of correlation with fitness is a fundamental characteristic of selective neutrality. Hence, selectively important traits become ...
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.87.5.2018
更新日期:1990-03-01 00:00:00
abstract::Covalently cross-linked pilus polymers displayed on the cell surface of Gram-positive bacteria are assembled by class C sortase enzymes. These pilus-specific transpeptidases located on the bacterial membrane catalyze a two-step protein ligation reaction, first cleaving the LPXTG motif of one pilin protomer to form 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.1800954115
更新日期:2018-06-12 00:00:00
abstract::A complementarity-determining region (CDR) of the mouse monoclonal antibody (mAb) F58 was constructed with specificity to a neutralization-inducing region of human immunodeficiency virus type 1 (HIV-1). The mAb has its major reactivity to the amino acid sequence I--GPGRA in the V3 viral envelope region. All CDRs inclu...
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.90.10.4374
更新日期:1993-05-15 00:00:00
abstract::Noniridescent coloration by the spongy keratin in parrot feather barbs has fascinated scientists. Nonetheless, its ultimate origin remains as yet unanswered, and a quantitative structural and optical description is still lacking. Here we report on structural and optical characterizations and numerical simulations of 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.1204383109
更新日期:2012-07-03 00:00:00
abstract::The dynamic responses of the hearing organ to acoustic overstimulation were investigated using the guinea pig isolated temporal bone preparation. The organ was loaded with the fluorescent Ca2+ indicator Fluo-3, and the cochlear electric responses to low-level tones were recorded through a microelectrode in the scala m...
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.95.12.7127
更新日期:1998-06-09 00:00:00
abstract::The cellular response to ionizing radiation (IR) includes induction of the c-jun and EGR1 early response genes. The present work has examined potential cytoplasmic signaling cascades that transduce IR-induced signals to the nucleus. The results demonstrate activation of the 40S ribosomal protein S6 kinase, pp90rsk, 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.91.12.5416
更新日期:1994-06-07 00:00:00
abstract::It is suggested that active transport, muscle contraction, and ribosomal translocation may all make use of a common allosteric mechanism in which ATP or GTP serves as both the effector and substrate and in which a conformational change in a protein (enzyme) moves or exerts a force on a second ligand. The enzymatic spl...
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.64.1.267
更新日期:1969-09-01 00:00:00
abstract::Results are reported showing that pituitary extracts stimulate growth of 3T3 cells, an established line of mouse fibroblast. Cells were cultured in medium containing an organic buffer (HEPES; N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid), which increases the serum requirement for cell growth. The pituitary grow...
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.70.9.2702
更新日期:1973-09-01 00:00:00
abstract::Indirect reciprocity is a mechanism for cooperation based on shared moral systems and individual reputations. It assumes that members of a community routinely observe and assess each other and that they use this information to decide who is good or bad, and who deserves cooperation. When information is transmitted pub...
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.1810565115
更新日期:2018-11-27 00:00:00
abstract::The heat shock protein (Hsp)70 family of molecular chaperones interacts with unfolded proteins through a C-terminal substrate-binding domain (SBD) that is controlled by nucleotide binding to the N-terminal domain. The ATPase cycle is regulated by cochaperones, including DnaJ proteins that accelerate ATP hydrolysis to ...
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.0702132105
更新日期:2008-01-29 00:00:00
abstract::Caseinolytic proteases (ClpPs) are large oligomeric protein complexes that contribute to cell homeostasis as well as virulence regulation in bacteria. Although most organisms possess a single ClpP protein, some organisms encode two or more ClpP isoforms. Here, we elucidated the crystal structures of ClpP1 and ClpP2 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.1219125110
更新日期:2013-07-09 00:00:00
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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.0409538102
更新日期:2005-03-29 00:00:00
abstract::Thyroid hormone is a major regulator of thermogenesis, acting both in peripheral organs and on central autonomic pathways. Mice heterozygous for a point mutation in thyroid hormone receptor α1 display increased thermogenesis as a consequence of high sympathetic brown fat stimulation. Surprisingly, despite the hypermet...
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.1310300110
更新日期:2013-10-01 00:00:00
abstract::Tramadol, previously only known as a synthetic analgesic, has now been found in the bark and wood of roots of the African medicinal tree Nauclea latifolia. At present, no direct evidence is available as to the biosynthetic pathway of its unusual skeleton. To provide guidance as to possible biosynthetic precursors, we ...
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.1506011112
更新日期:2015-07-07 00:00:00
abstract::Nanoparticle-based experimental therapeutics are currently being investigated in numerous human clinical trials. CALAA-01 is a targeted, polymer-based nanoparticle containing small interfering RNA (siRNA) and, to our knowledge, was the first RNA interference (RNAi)-based, experimental therapeutic to be administered to...
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.1411393111
更新日期:2014-08-05 00:00:00
abstract::Endosomal cargo travels through a dynamic vesicle network en route to degradation by lysosomes or recycling through the Golgi apparatus back to the cell surface. Rab5 is a key determinant of the early endosomes by organizing effector proteins in specific subdomains and mediating early endosome fusion. We find that ear...
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.0711707105
更新日期:2008-06-10 00:00:00
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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.74.11.4767
更新日期:1977-11-01 00:00:00
abstract::The POT1-TPP1 heterodimer, the major telomere-specific single-stranded DNA-binding protein in mammalian cells, protects chromosome ends and contributes to the regulation of telomerase. The recent discovery of telomeric RNA raises the question of how POT1 faithfully binds telomeric ssDNA and avoids illicit RNA binding ...
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.0911099107
更新日期:2010-01-12 00:00:00
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::Newly formed hepatic granulomas around Schistosoma mansoni eggs become progressively smaller during the chronic (greater than or equal to 15 weeks after infection) phase of the disease. This reduction in granuloma size, termed "modulation," is known to be caused in part by a T lymphocyte that can adoptively transfer m...
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.78.2.1152
更新日期:1981-02-01 00:00:00
abstract::An inwardly rectifying, ATP-regulated K+ channel with a distinctive molecular architecture, ROMK1, was recently cloned from rat kidney. Using patch clamp techniques, we have investigated the regulation of ROMK1 with particular emphasis on phosphorylation/dephosphorylation processes. Spontaneous channel rundown occurre...
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.91.17.8077
更新日期:1994-08-16 00:00:00
abstract::Cell cultures of Catharanthus roseus were supplied with [2-13C, 3-2H]-deoxyxylulose or [2-13C,4-2H]1-deoxyxylulose. Lutein and chlorophylls were isolated from the cell mass, and hydrolysis of the chlorophyll mixtures afforded phytol. Isotope labeling patterns of phytol and lutein were determined by 2H NMR and 1H,2H-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.96.4.1309
更新日期:1999-02-16 00:00:00
abstract::Insulin binding to insulin receptors, on skin fibroblasts established in culture from an infant with insulin resistance and clinical features of leprechaunism was markedly decreased in comparison with cultures from an age-matched control. By contrast, the binding of epidermal growth factor, a polypeptide growth factor...
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.76.11.5877
更新日期:1979-11-01 00:00:00
abstract::An electrophoretically slow albumin variant was detected with a phenotype frequency of about 1:1000 in Sweden and was also found in a family of Scottish descent from Kaikoura, New Zealand, and in five families in Tradate, Italy. Structural study established that the major variant component was arginyl-albumin, in whic...
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.87.10.3909
更新日期:1990-05-01 00:00:00
abstract::Social decisions require evaluation of costs and benefits to oneself and others. Long associated with emotion and vigilance, the amygdala has recently been implicated in both decision-making and social behavior. The amygdala signals reward and punishment, as well as facial expressions and the gaze of others. Amygdala ...
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.1514761112
更新日期:2015-12-29 00:00:00
abstract::An endogenous circadian biological clock controls the temporal aspects of life in most organisms, including rhythmic control of genes involved in clock output pathways. In the fungus Neurospora crassa, one pathway known to be under control of the clock is asexual spore (conidia) development. To understand more fully 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.93.23.13096
更新日期:1996-11-12 00:00:00
abstract::Genetic analysis has revealed that the accumulation of several chloroplast mRNAs of the green alga Chlamydomonas reinhardtii requires specific nucleus-encoded functions. To gain insight into this process, we have cloned the nuclear gene encoding the Mbb1 factor by genomic rescue of a mutant specifically deficient 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.97.26.14813
更新日期:2000-12-19 00:00:00