| 1. |
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| 2. |
- Björn, Lars Olof
(författare)
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Origins of photosynthesis
- 1995
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 376:6535, s. 25-26
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Hörlein, A. J., et al.
(författare)
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Ligand-independent repression by the thyroid hormone receptor mediated by a nuclear receptor co-repressor
- 1995
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 377:6548, s. 397-404
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Tidskriftsartikel (refereegranskat)abstract
- Thyroid-hormone and retinoic-acid receptors exert their regulatory functions by acting as both activators and repressors of gene expression. A nuclear receptor co-repressor (N-CoR) of relative molecular mass 270K has been identified which mediates ligand-independent inhibition of gene transcription by these receptors, suggesting that the molecular mechanisms of repression by thyroid-hormone and retinoic-acid receptors are analogous to the co-repressor-dependent transcriptional inhibitory mechanisms of yeast and Drosophila.
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| 4. |
- Kurokawa, R., et al.
(författare)
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Polarity-specific activities of retinoic acid receptors determined by a co-repressor.
- 1995
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 377:6548, s. 451-454
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Tidskriftsartikel (refereegranskat)abstract
- Retinoic acid receptors (RARs) and retinoid-X receptors (RXRs) activate or repress transcription by binding as heterodimers to DNA-response elements that generally consist of two direct repeat half-sites of consensus sequence AGGTCA. On response elements consisting of direct repeats spaced by five base pairs (DR + 5 elements), RAR/RXR heterodimers activate transcription in response to RAR-specific ligands, such as all-trans-retinoic acid (RA). In contrast, on elements consisting of direct repeats spaced by one base pair (DR + 1 elements), RAR/RXR heterodimers exhibit little or no response to activating ligands and repress RXR-dependent transcription. Here we show that ligand-dependent transactivation by RAR on DR + 5 elements requires the dissociation of a new nuclear receptor co-repressor, N-CoR, and recruitment of the putative co-activators p140 and p160. Surprisingly, on DR + 1 elements, N-CoR remains associated with RAR/RXR heterodimers even in the presence of RAR ligands, resulting in constitutive repression. These observations indicate that DNA-response elements can allosterically regulate RAR-co-repressor interactions to determine positive or negative regulation of gene expression.
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| 7. |
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| 8. |
- Los, Marek Jan, et al.
(författare)
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Requirement of an Ice/Ced-3 Protease for Fas/Apo-1-Mediated Apoptosis
- 1995
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 375:6526, s. 81-83
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Tidskriftsartikel (refereegranskat)abstract
- THE Fas/APO-1 receptor is one of the major regulators of apoptosis(1-7). We report here that Fas/APO-1-mediated apoptosis requires the activation of a new class of cysteine proteases, including interleukin-1 beta-converting enzyme (ICE)(8-10) which are homologous to the product of the Caenorhabditis elegans cell-death gene ced-3 (refs 11, 12). Triggering of Fas/APO-1 rapidly stimulated the proteolytic activity of ICE. Overexpression of ICE, achieved by electroporation and microinjection, strongly potentiated Fas/APO-1-mediated cell death. In addition, inhibition of ICE activity by protease inhibitors, as well as by transient expression of the pox virus-derived serpin inhibitor CrmA or an antisense ICE construct, substantially suppressed Fas/APO-1-triggered cell death. We conclude that activation of ICE or an ICE-related protease is a critical event in Fas/APO-1-mediated cell death.
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| 9. |
- Marcaide, J. M., et al.
(författare)
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Discovery of shell-like radio-structure in SN1993J
- 1995
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Ingår i: Nature. - London : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 373:6509, s. 44-45
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Tidskriftsartikel (refereegranskat)abstract
- SUPERNOVA explosions are poorly understood, partly because of difficulties in modelling them theoretically(1), and partly because there have been no supernovae observed in our Galaxy since the invention of the telescope. But the recent discovery(2) of supernova SN1993J in the nearby galaxy M81 offers an opportunity to investigate the evolution of the remnant, and its interaction with the surrounding interstellar medium, at high resolution. Here we present radio observations of SN1993J, made using very-long-baseline interferometry, which show the development of a shell structure. This 8-month-old radio shell is the youngest ever discovered in a supernova. The data suggest that the supernova explosion and the expanding shell of the remnant have nearly spherical symmetry, with small deviations where some parts of the shell are brighter than others. If these deviations arise because of variations in the density of the shell, this may reconcile earlier reports of symmetric radio emission(3) with the observed optical asymmetry(4,5), as the density variations could easily cause the latter. We infer that the radio emission is generated at the interface(6-9), where the surrounding gas is shocked by the ejecta.
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| 10. |
- PERLMANN, T, et al.
(författare)
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The sound of silence
- 1995
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 377:6548, s. 387-388
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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