Regulation gene activity

The role of PolyP in the cell envelope of prokaryotes may be connected with their anionic properties, important for providing the negative charge of this compartment. In addition, PolyPs may affect the cell-envelope functions by gene activity regulation, as will be discussed below. 

What are the concrete mechanisms of gene activity regulation in dosage compensation ... 

The family of apelin peptides is derived from a single gene, activate a single G-protein-coupled receptor and are substrates for the angiotensin converting enzyme-2 (ACE2). Apelins regulate cardiovascular function and fluid homeostasis. The apelin receptor also functions as a co-receptor for infection of CD4-positive cells by human immunodeficiency vims ( HIV). 

Histone acetylation is a reversible and covalent modification of histone proteins introduced at the e-amino groups of lysine residues. Histones and DNA form a complex - chromatin - which condenses DNA and controls gene activity. Current models interpret histone acetylation as a means to regulate chromatin activity. 

Histone tails are the N-terminal regions of histones which reach outside the nucleosomes. They are not essential for the formation in of nucleosomes but are required for the formation of higher-order chromatin structures. The histone tails are also known to be heavily posttranslationally modified by acetylation, phosphorylation, methylation, etc. and are important for the regulation of gene activity. 

Originally described in the immune system, NFAT proteins comprise a family of transcriptional factors that play key roles in many cellular processes that control not only immune responses but also the development, regulation, and differentiation of many other tissues. Activation of NFAT proteins results in the expression of specific sets of genes that regulate multiple cell functions [1,2]. 

Shuai K, Liu B (2005) Regulation of gene-activation pathways by PIAS proteins in the immune system. Nat Rev Immunol 5 593-605... 

Regulatory regions are transcriptional control sequences, which consist of promoters, response elements, enhancers and possibly silencers, located upstream of the start site of transcription. The overall effect on gene transcription is a sum of the contributions of these elements and the activities of proteins recruited to these sites. Promoters are located immediately upstream of the start site and initiate transcription. They often contain tissue- or cell-specific elements if the gene is not ubiquitously expressed. Enhancers are positive regulatory elements which function independently of orientation and distance from the genes they regulate. 

Iron-sulfur centers can participate in regulation mechanisms either directly, when they control the activity of an enzyme, or at a more integrated level, when they modulate the expression of some genes. The regulation mechanisms that have been elucidated so far involve either a change in the redox state or the interconversion of iron—sulfur centers. 

NF-xB activation has been linked with atherosclerosis (Andalibi etal., 1993 Liao etui., 1993). Mice that were maintained on an atherogenic diet, which resulted in ox-LDL accumulation in the liver and arteries, showed NF-xB activation in hepatic tissues. Furthermore, inflammatory gene up-regulation corresponded to the concentration of accumulated lipid peroxides as well as genetic susceptibility to fetty-streak development. 

Roy, D. Belsham, D. D. (2002). Melatonin receptor activation regulates GnRH gene expression and secretion in GT1-7 GnRH neurons. Signal transduction mechanisms. J. Biol. Chem. 277, 251-8. 

The second organism reported by Kilbane in addition to Rhodococcus as a potential host for BDS was Sphingomonas sp. AD109 [57], The dsz genes were regulated by an inducer activated by HPBS. This induction method, using the metabolite involved in the slowest step, could be apparently considered unsuccessful, since the inventors did not use it extensively subsequently. In fact, it was not very effective in breaking... 

Fruchart JC, Duriez P, Staels B. Peroxisome proliferator-activated receptor-alpha activators regulate genes governing lipoprotein metabolism, vascular inflammation and atherosclerosis. Curr Opin Lipidol 1999 10 245-257. 

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