摘要： We demonstrate that ATF3, a member of the ATF/CREB family of transcription factors, is induced in a variety of stressed tissues: mechanically injured liver, toxin-injured liver, blood-deprived heart, and postseizure brain. We also demonstrate that an ATF3-interacting protein, gadd153/Chop10, forms a nonfunctional heterodimer with ATF3: the heterodimer, in contrast to the ATM homodimer, does not bind to the ATF/cyclic AMP response element consensus site and does not repress transcription, Interestingly, ATF3 and gadd153/Chop10 are expressed in inverse but overlapping manners during the liver's response to carbon tetrachloride (CCl4): the level of gadd153/Chop10 mRNA is high in the normal liver and greatly decreases upon CCl4 treatment;the level of ATF3 mRNA, on the other hand, is low in the normal liver and greatly increases upon CCl4 treatment. We hypothesize that in nonstressed liver, gadd153/Chop10 inhibits the limited amount of ATF3 by forming an inactive heterodimer with it, whereas in CCl4-injured liver, the synthesis of gadd153/Chop10 is repressed, allowing the induced ATF3 to function.

关键词： Chemical structure   Energy   Anions   Basis sets   Chemical calculations  

摘要： Group 17 element fluorides EF(3) (E = Cl, Br, I) are well-known to undergo second-order Jahn-Teller symmetry breaking toward a T-shaped Ct, arrangement mainly due to a(1)'(HOMO)circle times e'(LUMO) mixing at the expected symmetric trigonal planar D-3h state. For heavy elements, the a(1)'HOMO is relativistically stabilized because of large element s-orbital participation. Hence, relativistic effects diminish the second-order Jahn-Teller term. This results in a large relativistic change in the F-eq-E-F-ax bonding angle of alpha(e)(R) - alpha(e)(NR) = 5.5 degrees in the case of AtF3 and causes an anomaly in the bond angle behavior down the group 17 compounds, alpha(ClF3) > alpha(BrF3) > alpha(AtF3) > alpha(IF3). Furthermore, the difference between the symmetric D-3h and the distorted C-2v structure Of AtF3 is only 10 kJ/mol at the coupled cluster level of theory, indicating that the measured F-eq-At-F-ax angle alpha(e) will be very sensitive upon the temperature applied in gas phase diffraction studies. Vibrational frequencies are predicted for all group 17 fluorides EF(3). As a consequence of the second-order Jahn-Teller distortion, the A(1) symmetric bending mode is strongly influenced by relativistic effects and becomes much lower in frequency compared to the B-1 out of plane mode for the heavier elements. With the exception of IF3, the symmetric D-3h structure represents a (metastable) weak local minimum at the MP2 level, rather than a transition state as expected. The D-3h point represents, however, a second-order saddle point at the HF level, and therefore, electron correlation seems to be responsible for changing the nature of the trigonal planar structure. Extended basis sets at the MP2 level as well as coupled cluster calculations were applied in order to obtain more accurate information for the energetics and structure of CIF3. These studies show, however, that the nature of the D-3h point is critically dependent upon the basis set (and the electron correlat

摘要： ATF3 gene, which encodes a member of the activating transcription factor/cAMP responsive element binding protein (ATF/CREB) family of transcription factors, is induced by many physiological stresses, As a step toward understanding the induction mechanisms, we isolated the human ATF3 gene and analyzed its genome organization and 5'-flanking region. We found that the human ATF3 mRNA is derived from four exons distributed over 15 kilobases. Sequence analysis of the 5'-flanking region revealed a consensus TATA box and a number of transcription factor binding sites including the AP-1, ATF/CRE, NF-kappa B, E2F, and Myc/Max binding sites. As another approach to understanding the mechanisms by which the ATF3 gene is induced by stress signals, we studied the regulation of the ATF3 gene in tissue culture cells by anisomycin, an approach that has been used to study the stress responses in tissue culture cells, We showed that anisomycin at a low concentration activates the ATF3 promoter and stabilizes the ATF3 mRNA, Significantly, co-transfection of DNAs expressing ATF2 and c-Jun activates the ATF3 promoter, A possible mechanism implicating the C-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) stress-inducible signaling pathway in the induction of the ATF3 gene is discussed.

摘要： ATF3 is a member of the mammalian activating transcription factor/cAMP responsive element binding protein (ATF/CREB) family of transcription factors. In this report, we demonstrate that, contrary to the implication of its name, ATF3 represses rather than activates transcription from promoters with ATF sites. We also present evidence suggesting that one possible mechanism by which ATF3 represses transcription is to stabilize inhibitory co-factors at the promoter. In addition, we describe a naturally occurring, alternatively spliced, form of ATF3: ATF3 Delta Zip. ATF3 Delta Zip lacks the leucine zipper domain and does not bind to DNA. In contrast to ATF3, ATF3 Delta Zip stimulates transcription, presumably by sequestering inhibitory co-factors away from the promoter. It is possible that ATF3 Delta Zip is a physiologically important regulator and that it, together with ATF3, regulates the expression of specific target genes.

摘要： ATF3 is a member of the mammalian activating transcription factor/cAMP responsive element binding protein (ATF/CREB) family of transcription factors. In this report, we demonstrate that, contrary to the implication of its name, ATF3 represses rather than activates transcription from promoters with ATF sites. We also present evidence suggesting that one possible mechanism by which ATF3 represses transcription is to stabilize inhibitory co-factors at the promoter. In addition, we describe a naturally occurring, alternatively spliced, form of ATF3: ATFSΔZip. ATFSΔZip lacks the leucine zipper domain and does not bind to DNA. In contrast to ATF3, ATF3ΔZip stimulates transcription, presumably by sequestering inhibitory co-factors away from the promoter. It is possible that ATF3ΔZip is a physiologically important regulator and that it, together with ATF3, regulates the expression of specific target genes.

关键词： AIRCRAFT ENGINES, JET AND TURBINE--Design  

摘要： The ATF3 was designed to give the small executive jet a coast- tocoast range by reducing the fuel consumption by 40% from that of existing engines. The basic engine nominally is sized at the 5000- lb thrust level for sea- level operation.