共查询到20条相似文献,搜索用时 328 毫秒
1.
2.
3.
4.
RNA-mediated gene silencing 总被引:21,自引:0,他引:21
5.
6.
7.
8.
Tung SY Hong JY Walz T Moazed D Liou GG 《Cellular and molecular life sciences : CMLS》2012,69(4):641-650
In the cell, many small endogenous metabolic molecules are involved in distinct cellular functions such as modulation of chromatin
structure and regulation of gene expression. O-acetyl-ADP-ribose (AAR) is a small metabolic molecule that is generated during NAD-dependent deacetylation by Sir2. Sir2
regulates gene expression, DNA repair, and genome stability. Here, we developed a novel chromatin affinity-precipitation (ChAP)
method to detect the chromatin fragments at which small molecules interact with binding partners. We used this method to demonstrate
that AAR associated with heterochromatin. Moreover, we applied the ChAP method to whole genome tiling array chips to compare
the association of AAR and Sir2. We found that AAR and Sir2 displayed similar genomic binding patterns. Furthermore, we identified
312 potential association cluster regions of AAR. The ChAP assay may therefore be a generally useful strategy to study the
small molecule association with chromosomal regions. Our results further suggest that the small metabolic molecule AAR associates
with silent chromatin regions in a Sir2-dependent manner and provide additional support for the role of AAR in assembly of
silent chromatin. 相似文献
9.
10.
11.
T. Jenuwein G. Laible R. Dorn G. Reuter 《Cellular and molecular life sciences : CMLS》1998,54(1):80-93
The SET domain is a 130-amino acid, evolutionarily conserved sequence motif present in chromosomal proteins that function
in modulating gene activities from yeast to mammals. Initially identified as members of the Polycomb- and trithorax-group (Pc-G and trx-G) gene families, which are required to maintain expression boundaries of homeotic selector (HOM-C) genes,
SET domain proteins are also involved in position-effect-variegation (PEV), telomeric and centromeric gene silencing, and
possibly in determining chromosome architecture. These observations implicate SET domain proteins as multifunctional chromatin
regulators with activities in both eu- and heterochromatin – a role consistent with their modular structure, which combines
the SET domain with additional sequence motifs of either a cysteine-rich region/zinc-finger type or the chromo domain. Multiple
functions for chromatin regulators are not restricted to the SET protein family, since many trx-G (but only very few Pc-G)
genes are also modifiers of PEV. Together, these data establish a model in which the modulation of chromatin domains is mechanistically
linked with the regulation of key developmental loci (e.g. HOM-C). 相似文献
12.
13.
14.
15.
16.
17.
Summary Neurones ofHelix aspersa were excited and strength/duration curves plotted for an active and a silent cell. Experimental response latencies were longer than predicted by the theoretical relationship at low currents. The time constant of excitation was longer in the silent than the active cell.The work was supported by a studentship awarded by the Science Research Council. 相似文献
18.
El-Osta A 《Cellular and molecular life sciences : CMLS》2004,61(17):2135-2136
19.
20.
Maria Luiza Beçak Kazumi Fukuda Pizzocaro 《Cellular and molecular life sciences : CMLS》1980,36(2):164-166
Summary Previtellogenic oocytes ofOdontophrynus americanus display hundreds of chromatin circles. Electron microscopy of spread preparations of isolated nuclei shows that the circles originate from the chromatin. The circles change their morphology and form new copies. The length of the DNA packed in the nucleosomal circles is about 2.5–3.5 m or multiples of this value. Assuming that histones need not be removed from chromatin before DNA replication3 we suggest that the circles might belong to the process of rDNA amplification.This work was supported by grants from the Brazilian CNPq, FAPESP and FEDIB.We thank Dr A. Brunner Jr for the use of the electron microscope and Dr N. Leon for his valuable help. 相似文献