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ATM requirement in gene expression responses to ionizing radiation in human lymphoblasts and fibroblasts 总被引:3,自引:0,他引:3
Innes CL Heinloth AN Flores KG Sieber SO Deming PB Bushel PR Kaufmann WK Paules RS 《Molecular cancer research : MCR》2006,4(3):197-207
The heritable disorder ataxia telangiectasia (AT) is caused by mutations in the AT-mutated (ATM) gene with manifestations that include predisposition to lymphoproliferative cancers and hypersensitivity to ionizing radiation (IR). We investigated gene expression changes in response to IR in human lymphoblasts and fibroblasts from seven normal and seven AT-affected individuals. Both cell types displayed ATM-dependent gene expression changes after IR, with some responses shared and some responses varying with cell type and dose. Interestingly, after 5 Gy IR, lymphoblasts displayed ATM-independent responses not seen in the fibroblasts at this dose, which likely reflect signaling through ATM-related kinases, e.g., ATR, in the absence of ATM function. 相似文献
13.
The temporal availability of propagules is a critical factor in sustaining pioneer riparian tree populations along snowmelt-driven
rivers because seedling establishment is strongly linked to seasonal hydrology. River regulation in semi-arid regions threatens
to decouple seed development and dispersal from the discharge regime to which they evolved. Using the lower Tuolumne River
as a model system, we quantified and modeled propagule availability for Populus fremontii (POFR), Salix gooddingii (SAGO), and Salix exigua (SAEX), the tree and shrub species that dominate near-channel riparian stands in the San Joaquin Basin, CA. A degree-day
model was fit to field data of seasonal seed density and local temperature from three sites in 2002–2004 to predict the onset
of the peak dispersal period. To evaluate historical synchrony of seed dispersal and seasonal river hydrology, we compared
peak spring runoff timing to modeled peak seed release periods for the last 75 years. The peak seed release period began on
May 15 for POFR (range April 23–June 10), May 30 for SAGO (range May 19–June 11) and May 31 for SAEX (range May 8–June 30).
Degree-day models for the onset of seed release reduced prediction error by 40–67% over day-of-year means; the models predicted
best the interannual, versus site-to-site, variation in timing. The historical analysis suggests that POFR seed release coincided
with peak runoff in almost all years, whereas SAGO and SAEX dispersal occurred during the spring flood recession. The degree-day
modeling approach reduce uncertainty in dispersal timing and shows potential for guiding flow releases on regulated rivers
to increase riparian tree recruitment at the lowest water cost. 相似文献
14.
Wagner A. Chiba de Castro Rafael O. Xavier Federico H. L. Garrido Jair H. C. Romero Cleto K. Peres Ruberval C. da Luz 《Journal of Plant Ecology》2019,12(4):713
Aims
Invasive plants modify the structure and functioning of natural environments and threat native plant communities. Invasive species are often favored by human interference such as the creation of artificial forest edges. Field removal experiments may clarify if invasive plants are detrimental to native plant regeneration and how this is related to other local factors. We assessed the joint effect of environment and competition with the invasiveTradescantia zebrinaon tree species recruitment in an Atlantic Forest fragment. 相似文献
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Maria Letizia Ciavatta Stella García‐Matucheski Marianna Carbone Guido Villani Maria Rosaria Nicotera Claudia Muniain Margherita Gavagnin 《化学与生物多样性》2017,14(9)
The lipophilic extracts of two marine aeolid nudibranch molluscs of the genus Spurilla collected in distinct geographical areas have been chemically analyzed. The Et2O extracts of the nudibranchs were dominated by the presence of usual fatty acids and sterols and contained terpenoid compounds 1 – 3 as minor metabolites. Spurillin A ( 1 ) and spurillin B ( 3 ) were new molecules whereas cis‐γ‐monocyclofarnesol ( 2 ) was already reported in the literature as a synthesis product. Interestingly, bursatellin ( 4 ), previously isolated from anaspidean molluscs of the genus Bursatella, was found in the butanol extract of both Spurilla species. Compounds 1 – 4 were not detected in the extracts of the sea‐anemone preys collected together with the molluscs. 相似文献
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Liselotte W. Wijsman Anton J. M. de Craen Stella Trompet Jacobijn Gussekloo David J. Stott Nicolas Rodondi Paul Welsh J. Wouter Jukema Rudi G. J. Westendorp Simon P. Mooijaart 《PloS one》2013,8(3)
Background
Subclinical thyroid dysfunction has been implicated as a risk factor for cognitive decline in old age, but results are inconsistent. We investigated the association between subclinical thyroid dysfunction and cognitive decline in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER).Methods
Prospective longitudinal study of men and women aged 70–82 years with pre-existing vascular disease or more than one risk factor to develop this condition (N = 5,154). Participants taking antithyroid medications, thyroid hormone supplementation and/or amiodarone were excluded. Thyroid function was measured at baseline: subclinical hyper- and hypothyroidism were defined as thyroid stimulating hormones (TSH) <0.45 mU/L or >4.50 mU/L respectively, with normal levels of free thyroxine (FT4). Cognitive performance was tested at baseline and at four subsequent time points during a mean follow-up of 3 years, using five neuropsychological performance tests.Results
Subclinical hyperthyroidism and hypothyroidism were found in 65 and 161 participants, respectively. We found no consistent association of subclinical hyper- or hypothyroidism with altered cognitive performance compared to euthyroid participants on the individual cognitive tests. Similarly, there was no association with rate of cognitive decline during follow-up.Conclusion
We found no consistent evidence that subclinical hyper- or hypothyroidism contribute to cognitive impairment or decline in old age. Although our data are not in support of treatment of subclinical thyroid dysfunction to prevent cognitive dysfunction in later life, only large randomized controlled trials can provide definitive evidence. 相似文献20.
Primosome assembly protein PriA functions in the assembly of the replisome at forked DNA structures. Whereas its N-terminal DNA binding domain (DBD) binds independently to DNA, the affinity of DBD protein for forked structures is relatively weak. Although the PriA helicase domain (HD) is required for high affinity fork binding, HD protein had very low affinity for DNA. It had only low levels of ATPase activity, and it hydrolyzed ATP when DNA was absent whereas PriA did not. HD catalyzed unwinding of a minimal substrate composed of a duplex with a 3' single-stranded tail. Single-strand binding protein (SSB) bound to the tail of this substrate inhibited this reaction by full-length PriA but enhanced the reaction by HD. SSB stabilized binding of PriA but not of DBD or HD to duplexes with a 5' or 3' single-stranded tail. On forked substrates SSB enhanced helicase action on the lagging-strand arm by PriA but not by HD. The results indicate that synergy of the DBD and HD allows stable binding at the interface between duplex and single-stranded DNA bound by SSB. This mode of binding may be analogous to fork binding, which orients the helicase to act on the lagging-strand side of the fork. 相似文献