Transcriptional silencing

Marban C, Suzanne S, Dequiedt F, de Walque S, Redel L, Van Lint C, Aunis D, Rohr O (2007) Recruitment of chromatin-modifying enzymes by CTIP2 promotes HIV-1 transcriptional silencing. EMBO J 26(2) 412-423... 

Plant phytoene synthase (Psy) has been used in a variety of transgenics. As noted above, P yl over-expression under a strong constitutive promoter caused a decrease in carotenoid accumulation, probably due to transcription silencing. Similarly, over-expression of the gene sequence backward (antisense) also silenced activity. In another approach to over-expression of tomato 1 in fruits, a synthetic alternative in which the third position of each codon was changed in order to avoid transcriptional silencing was successful in conditioning an increase in carotenoid accumulation. 

Sharan C, Hamilton NM, Parl AK, Singh PK, Chaudhuri G. Identification and characterization of a transcriptional silencer upstream of the human BRCA2 gene. Biochem Biophys Res Commun 1999 265J2] 285—290. 

UBP3/ S. cerevisiae, polyubiquitin accumulation transcriptional silencing inhibitor,... 

The role of H2A.Z does not appear to be confined to transcriptional activation. Deletion of the gene for H2A.Z in S. cerevisiae also leads to defects in transcriptional silencing at the silent mating locust and telomeres [46]. Thus, H2A.Z may participate in the formation of specialized chromatin structures that can be used for either activation or silencing. 

Amedeo, P., Habu, Y., Afsar, K., Scheid, O.M., and Paszkowski, J. (2000) Disruption of the plant gene MOM releases transcriptional silencing of methylated genes. Nature 405, 203-206. 

In multicellular eukaryotes, DNA methylation is associated with transcriptional silencing [3]. In these organisms, DNA methylation has been observed exclusively on the C5 position of the cytosine ring and is frequently found in CpG-rich regions. This process is attributed to the action of DNA methyltransferases (DNMTs), which utilize the cofactor, S-adenosyl-L-methionine. Approximately half of all human genes have CpG islands in their promoter regions but these stretches of DNA are typically... 

Transcriptional repression by DNA methylation is achieved by various modes of action. In one such mechanism, DNA methylation simply inhibits the binding of a transcription factor [17[. By a more complex means of action, a number of DNA methyl-binding proteins potentiate transcriptional silencing. In some cases, binding is accompanied by the action of an associated histone-modifying enzyme. 

Braunstein, M., Rose, A.B., Holmes, S.G., Allis, C.D. and Broach, J.R. (1993) Transcriptional silencing in yeast is associated with reduced nucleosome acetylation. Genes e[ Development, 7, 592-604. 

Imai, S., Armstrong, C.M., Kaeberlein, M. and Guarente, L. (2000) Transcriptional silencing and longevity protein Sir2 is an NAD-dependent histone deacetylase. Nature, 403, 795-800. 

Gottlieb, S. and Esposito, R.E. (1989) A new role for a yeast transcriptional silencer gene, SIR2, in regulation of recombination in ribosomal DNA. Cell, 56, 771-776. 

Methylation of certain bases within DNA molecules plays a major role in gene expression, as is evidenced by the transcriptional silencing of X chromosome genes through methylation. The following are recent reviews on the molecular and physical properties of these enzymes [EC 2.1.1.x]. See also specific methyltransferase... 

Jackson AL, Burchard J, Schelter J et al (2006) Widespread siRNA off-target transcript silencing mediated by seed region sequence complementarity. RNA 12 1179-1187... 

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