Effects on transcription factor

Drugs of abuse have profound effects on transcription factors and gene expression 924... 

Drugs of abuse have profound effects on transcription factors and gene expression. These effects are clearly important for long-lasting changes in brain function. Two transcription factors strongly implicated in addiction are CREB and AFosB [23], CREB is important for learning and memory and is activated by phosphorylation. 

Eiaia ES and Sohn OS (2001) Mechanisms of orga-noselenium compounds in chemoprevention effects on transcription factor-DNA Binding. Nutr Cane 40 28-33. 

The third mechanism involves oxidation-reduction effects on transcription factors to alter their activation state. For example, the transcription factor NF-kappa-P that is involved in inflammatory mechanisms is activated by oxidation and is inhibited by dietary antioxidants. 

Harmine proved to be a potent angiogenic inhibitor, which was extensively evaluated by in vitro and in vivo experiments, in vitro, it was able to reduce different steps of neo-vessel formation by VEGF-induced HUVEC, including proliferation, motility, invasion, and tube formation. Additionally, harmine showed inhibitory effect on transcription factors related to crucial tumor development and angiogenesis process. It reduced the translocation and activation of... 

Figure 43-11. The hormone response transcription unit. The hormone response transcription unit is an assembly of DNA elements and bound proteins that interact, through protein-protein interactions, with a number of coactivator or corepressor molecules. An essential component is the hormone response element which binds the ligand (A)-bound receptor (R). Also Important are the accessory factor elements (AFEs) with bound transcription factors. More than two dozen of these accessory factors (AFs), which are often members of the nuclear receptor superfamily, have been linked to hormone effects on transcription. The AFs can interact with each other, with the liganded nuclear receptors, or with coregulators. These components communicate with the basal transcription complex through a coregulator complex that can consist of one or more members of the pi 60, corepressor, mediator-related, or CBP/p300 families (see Table 43-6).

Chou W-Y, Stewart MJ, Carr LG, Zheng D, Stewart TR, Williams A, Pinaire J, Crabb DW. An A/G polymorphism in the promoter of mitochondrial aldehyde dehydrogenase (ALDH2) effects of the sequence variant on transcription factor binding and promoter strength. Alcohol Clin Exp Res 1999 26 963-968. 

Hu, Y., Jin, X., and Snow, E.T., Effect of arsenic on transcription factor AP-1 and Nfkap-paB DNA binding activity and related gene expression, Toxicol. Lett., 133, 33, 2002. 

Ouyang, Y. L., Li S., and Pestka J.J. Effects of vomitoxin (deoxynivalenol) on transcription factor NF-kappa B/Rel binding activity in murine EL-4 thymoma and primary CD4+ T cells. Toxicol. Appl. Pharmacol. 140, 328, 1996. 

Numerous studies have analyzed the regulatory effects of RNI on transcription factors and transcriptional regulation. Although outside the main focus of this article, to summarize these primary observations we provide a table showing several transcription factors and their regulation under the impact of RNI (Table 13.1). For extensive coverage of the primary literature we refer to a number of review articles [11-14],... 

Rosenbauer, F., Koschmieder, S., Steidl, U. and Tenen, D.G. (2005) Effect of transcription factor concentrations on leukemic stem cells. Blood 106, 1519 1524. 

Another approach to regulating the activity of transcription factors is to modify the chromatin state and therefore the accessibility of the promoter and TF binding sites (78, 79). Chromatin states are modulated partially by posttranslational modifications of the histones in nucleosomes, which have significant effects on transcription levels (14, 80). These modifications include phosphorylation, methylation, acetylation, and ubiquitination (80, 81). An early indication of the importance of these covalent modifications on transcription emerged from the observation... 

We have seen how interactions between DNA-binding proteins such as CAP and RNA polymerase can activate transcription in prokaryotic cells (Section 31.1.6). Such protein-protein interactions play a dominant role in eukaryotic gene regulation. In contrast with those of prokaryotic transcription, few eukaryotic transcription factors have any effect on transcription on their own. Instead, each factor recruits other proteins to build up large complexes that interact with the transcriptional machinery to activate or repress Panscription. 

The phosphorylation of histone H3 can have a repressive or activating effect on transcription. Members of the MAP kinases (see Chapter 10) that are responsible for this phosphorylation have been identified, providing a link between growth factor stimulation and transcription activation at the level of histone modification. H3 phosphorylation has been also recognized as part of a complex signaling mechanism that operates in the condensation/decondensation of chromatin during the cell cycle. Furthermore, histone HI phosphorylation has been linked to the relief of transcription repression. 

Which statement is NOT TRUE regarding the effect of transcription-factor phosphorylation on protein activity ... 

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