Abstract:
:In adipocytes, adenylate cyclase is positively regulated by beta-adrenergic agents and negatively regulated by adenosine. Incubation of adipocytes with adenosine deaminase relieves the inhibition of adenylate cyclase by destroying the adenosine that the cells release into the medium. When adipocytes are incubated with adenosine deaminase and the beta-adrenergic agent isoproterenol, most of their ATP is converted to AMP in 5 min. Either isoproterenol or adenosine deaminase alone has little or no effect. In the additional presence of the phosphodiesterase inhibitor 4-(3-butoxy-4-methoxybenzyl)imidazolidin-2-one (Ro 20-1724) cAMP accumulates instead of AMP. Under these conditions, cAMP represents 40-50% of the total intracellular adenine nucleotides, and ATP only 5%. N6-(L-2-phenylisopropyl)adenosine, a deaminase-resistant adenosine agonist, prevents beta-adrenergic stimulation. 8-(p-Sulfophenyl)theophylline and 3-isobutyl-1-methylxanthine are both adenosine antagonists that can replace the deaminase in permitting beta-adrenergic stimulation of adenylate cyclase, but only the latter also inhibits the phosphodiesterase and causes accumulation of cAMP. When the ATP-depleted adipocytes are washed with fresh medium, the nucleoside triphosphate level can be restored within 5 min. The ATP-restored adipocytes can respond rapidly to a second dose of isoproterenol and adenosine antagonist. These findings point out the important role of adenosine in controlling adenylate cyclase activity and the possible involvement of adenylate cyclase in the control of energy flow in rat adipocytes.
journal_name
Proc Natl Acad Sci U S Aauthors
Chung FZ,Weber HW,Appleman MMdoi
10.1073/pnas.82.6.1614subject
Has Abstractpub_date
1985-03-01 00:00:00pages
1614-7issue
6eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::Neurons in macaque primary visual cortex are spatially arranged by their global topographic position and in at least three overlapping local modular systems: ocular dominance columns, orientation pinwheels, and cytochrome oxidase (CO) blobs. Individual neurons in the blobs are not tuned to orientation, and populations...
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.0500291102
更新日期:2005-03-15 00:00:00
abstract::Scores of homeobox gene-encoded transcription factors are expressed in a definite spatiotemporal pattern during embryogenesis and regulate a series of as yet unidentified target genes to help coordinate the morphogenetic process. We have suggested that homeobox gene products modulate the expression of adhesion molecul...
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.90.14.6557
更新日期:1993-07-15 00:00:00
abstract::SLAM (signaling lymphocyte activation molecule)-associated protein (SAP) is a Src homology 2 (SH2) domain-containing adaptor expressed in T cells and natural killer cells. Its essential role in immune responses is underscored by the recent finding that mutations in SAP result in a rare but fatal X-linked lymphoprolife...
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.0606624103
更新日期:2006-09-26 00:00:00
abstract::Under steady-state conditions, the immune system is poised to sense and respond to the microbiota. As such, immunity to the microbiota, including T cell responses, is expected to precede any inflammatory trigger. How this pool of preformed microbiota-specific T cells contributes to tissue pathologies remains unclear. ...
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.2003022117
更新日期:2020-07-14 00:00:00
abstract::Pain reduction and enhancement can be produced by means of conditioning procedures, yet the role of awareness during the acquisition stage of classical conditioning is unknown. We used psychophysical measures to establish whether conditioned analgesic and hyperalgesic responses could be acquired by unseen (subliminall...
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.1504567112
更新日期:2015-06-23 00:00:00
abstract::Metastatic spread is the leading cause of cancer mortality. Breast cancer (BCa) metastatic recurrence can happen years after removal of the primary tumor. Here we show that Ubc13, an E2 enzyme that catalyzes K63-linked protein polyubiquitination, is largely dispensable for primary mammary tumor growth but is required ...
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.1414358111
更新日期:2014-09-23 00:00:00
abstract::Immediately after focal retinal lesions, receptive fields (RFs) in primary visual cortex expand considerably, even when the retinal damage is limited to the photoreceptor layer. The time course of these changes suggests that mere lack of stimulation in the vicinity of the RF accompanied by stimulation in the surroundi...
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.89.17.8366
更新日期:1992-09-01 00:00:00
abstract::Broken-cell preparations of Salmonella typhimurium rapidly incorporated 75Se from 75SeO3(2-) into tRNA by an ATP-dependent process. Selenium incorporation in the presence of 50 microM 75SeO3(2-) (0.8-1 pmol per A260 unit) was enhanced by the selenocysteine precursor, O-acetyl-L-serine (to 3.7 pmol per A260 unit). This...
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.87.16.6341
更新日期:1990-08-01 00:00:00
abstract::The major Hsp70 of the mitochondrial matrix (Ssc1 in yeast) is critically important for the translocation of proteins from the cytosol, across the mitochondrial inner membrane, and into the matrix. Tim44, a peripheral inner membrane protein with limited sequence similarity to the J domain of J-type cochaperones, tethe...
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.1936150100
更新日期:2003-11-25 00:00:00
abstract::Guanylin and uroguanylin are intestinal peptides that stimulate chloride secretion by activating a common set of receptor-guanylate cyclase signaling molecules located on the mucosal surface of enterocytes. High mucosal acidity, similar to the pH occurring within the fluid microclimate domain at the mucosal surface 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.94.6.2705
更新日期:1997-03-18 00:00:00
abstract::Inbred Lewis (LEW/N) female rats develop an arthritis in response to group A streptococcal cell wall peptidoglycan polysaccharide (SCW), which mimics human rheumatoid arthritis. Histocompatible Fischer (F344/N) rats do not develop arthritis in response to the same SCW stimulus. To evaluate this difference in inflammat...
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.86.7.2374
更新日期:1989-04-01 00:00:00
abstract::A long-term electrophoretic survey of genetic variants of serum albumin has identified an alloalbumin in 589 unrelated individuals in Italy. The alloalbumins were classified electrophoretically into 17 types. The number of unrelated carriers for each type varied from 1 for several variants reported here to 103 for alb...
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.87.22.8721
更新日期:1990-11-01 00:00:00
abstract::Veratridine or high potassium concentration increased guanosine 3',5'-cyclic monophosphate (cGMP) levels in neuroblastoma cells of clone N1E-115 without affecting levels of adenosine 3',5'-cyclic monophosphate (cAMP). The increases in cGMP appear to be a direct result of the depolarizing action of these agents and not...
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.75.12.6295
更新日期:1978-12-01 00:00:00
abstract::Angiosperms are the largest and most successful clade of land plants with >250,000 species distributed in nearly every terrestrial habitat. Many phylogenetic studies have been based on DNA sequences of one to several genes, but, despite decades of intensive efforts, relationships among early diverging lineages and sev...
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.0709121104
更新日期:2007-12-04 00:00:00
abstract::IDIOTYPY HAS BEEN STUDIED IN ANTIBODIES AGAINST A PROTEIN ANTIGEN: hen ovalbumin. Various fractions of antisera to hen ovalbumin have been compared from the standpoint of the idiotypic specificities found on the immunoglobulins that they contain. Idiotypic specificities were found to be common to (a) antibodies that 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.68.10.2616
更新日期:1971-10-01 00:00:00
abstract::When the lactose (lac) permease of Escherichia coli is expressed from the lac promoter at relatively low rates, deletion of amino acid residues 2-8 (delta 7) or 2-9 (delta 8) from the hydrophilic N terminus has a relatively minor effect on the ability of the permease to catalyze active lactose transport. Activity is 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.89.8.3180
更新日期:1992-04-15 00:00:00
abstract::HIV type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry into target cells. Here we show that the HIV-1 envelope gp120 (Env) activates multiple ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. Env from both CCR5-dependent JRFL (R5) 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.090521697
更新日期:2000-04-25 00:00:00
abstract::Tumor heterogeneity confounds cancer diagnosis and the outcome of therapy, necessitating analysis of tumor cell subsets within the tumor mass. Elevated expression of hyaluronan (HA) and HA receptors, receptor for HA-mediated motility (RHAMM)/HA-mediated motility receptor and cluster designation 44 (CD44), in breast tu...
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.1402383111
更新日期:2014-04-29 00:00:00
abstract::Microorganisms have mechanisms to sense their environment and rapidly adapt to survive changes in conditions. In Streptomyces albus, various transcriptional repressors mediate the induction of heat shock genes. The RheA repressor regulates the synthesis of HSP18, a small heat shock protein, which plays a role in therm...
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.070426197
更新日期:2000-03-28 00:00:00
abstract::The cytokines interleukin (IL) 4 and IL-13 induce many of the same biological responses, including class switching to IgE and induction of major histocompatibility complex class II antigens and CD23 on human B cells. It has recently been shown that IL-4 induces the tyrosine phosphorylation of a 170-kDa protein, a subs...
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.92.17.7681
更新日期:1995-08-15 00:00:00
abstract::Circulating platelets have important functions in thrombosis and in modulating immune and inflammatory responses. However, the role of platelets in innate immunity to bacterial infection is largely unexplored. While human platelets rapidly kill Staphylococcus aureus, we found the neonatal pathogen group B Streptococcu...
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.1815572116
更新日期:2019-04-09 00:00:00
abstract::Human craniofacial data were used to assess the similarities and differences between recent and prehistoric Old World samples, and between these samples and a similar representation of samples from the New World. The data were analyzed by the neighbor-joining clustering procedure, assisted by bootstrapping and by cano...
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.171305898
更新日期:2001-08-14 00:00:00
abstract::Two main types of peroxisomal targeting signals have been identified that reside either at the extreme C terminus (PTS1) or the N terminus (PTS2) of the protein. In the methylotrophic yeast Hansenula polymorpha the majority of peroxisomal matrix proteins are of the PTS1 type. Thus far, for H. polymorpha only amine oxi...
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.91.26.12985
更新日期:1994-12-20 00:00:00
abstract::Seed plants vary tremendously in size and morphology; however, variation and covariation in plant traits may be governed, at least in part, by universal biophysical laws and biological constants. Metabolic scaling theory (MST) posits that whole-organismal metabolism and growth rate are under stabilizing selection 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.1709141115
更新日期:2018-03-27 00:00:00
abstract::CD11c, also known as integrin alpha X, is the most widely used defining marker for dendritic cells (DCs). CD11c can bind complement iC3b and mediate phagocytosis in vitro, for which it is also referred to as complement receptor 4. However, the functions of this prominent marker protein in DCs, especially in vivo, rema...
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.1805542115
更新日期:2018-06-26 00:00:00
abstract::The geographical structure of a population distributed continuously and homogeneously along an infinite linear habitat is explored. The analysis is restricted to a single locus in the absence of selection, and every mutant is assumed to be new to the population. An explicit formula is derived for the probability 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.71.8.2932
更新日期:1974-08-01 00:00:00
abstract::2(S)-dihydroxypropanesulfonate (DHPS) is a microbial degradation product of 6-deoxy-6-sulfo-d-glucopyranose (sulfoquinovose), a component of plant sulfolipid with an estimated annual production of 1010 tons. DHPS is also at millimolar levels in highly abundant marine phytoplankton. Its degradation and sulfur recycling...
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.2003434117
更新日期:2020-07-07 00:00:00
abstract::Type IV pili are thin filaments that extend from the poles of a diverse group of bacteria, enabling them to move at speeds of a few tenths of a micrometer per second. They are required for twitching motility, e.g., in Pseudomonas aeruginosa and Neisseria gonorrhoeae, and for social gliding motility in Myxococcus xanth...
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.121171698
更新日期:2001-06-05 00:00:00
abstract::Clinical and experimental observations indicate a role for VEGF secreted by the retinal pigment epithelium (RPE) in the maintenance of the choriocapillaris (CC). VEGF in mice is produced as three isoforms, VEGF120, VEGF164, and VEGF188, that differ in their ability to bind heparan sulfate proteoglycan. RPE normally pr...
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.0905010106
更新日期:2009-11-03 00:00:00
abstract::Accurate modification of the 3 billion-base-pair human genome requires tools with exceptional sequence specificity. Here, we describe a general strategy for the design of enzymes that target a single site within the genome. We generated chimeric zinc finger recombinases with cooperative DNA-binding and catalytic speci...
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.0812502106
更新日期:2009-03-31 00:00:00