Coordinated gene expression

JM Claverie. Computational methods for the identification of differential and coordinated gene expression. Hum Mol Genet 8 1821-1832, 1999. 

Valor, L.M., Charlesworth, P., Humphreys, L., Anderson, C.N. and Grant, S.G. (2007) Network activity-independent coordinated gene expression program for synapse assembly. Proc. Natl. Acad. Sci. U.S.A. 704(11), 4658-4663. 

A unique example of structural identification of a biofunctional molecule was reported recently by Hughson and coworkers in 2002.19 Autoinducer-2 (AI-2) is a universal signal for interspecies communication (quorum sensing) in bacteria, which allows bacteria to coordinate gene expression. The structure of AI-2 remained elusive until 2002, when the X-ray crystallographic analysis of AI-2 sensor protein (Lux P) in a complex with AI-2 was successfully carried out. As shown in Table 1.2, the bound ligand AI-2 was a furanosyl borate diester 8.19 In this particular case, the structure of a biofunctional molecule could be elucidated even without isolating it. 

KEELING, C.I., BLOMQUIST, G.J., TITTIGER, C., Coordinated gene expression for pheromone biosynthesis in the pine engraver beetle, Ips pini (Coleoptera Scolytidae). Naturwissenschaften, 2004, 91, 324-328. 

Jump DB et al Coordinate regulation of glycolytic and lipogenic gene expression by polyunsaturated fatty acids. J Lipid Res... 

Shekels, L., Anway, R.E., Lin, J., Kennedy, M.W., Garside, P., Lawrence, C.E. and Ho, S.B. (2000) Coordinated Muc2 and Muc3 mucin gene expression in Trichinella spiralis infection in wild-type and cytokine deficient mice. Infection and Immunity (submitted). 

A considerable number of transcription factors have reactive cysteine residues, which enable them to respond to the redox conditions in the cell. Since cadmium perturbs redox homeostasis, it can affect this class of transcription factors. If cadmium can displace the tetra-coordinate zinc atoms in zinc finger-containing transcription factors, it will affect them as well. Many of the pathways involving activation and inactivation of transcription factors involve kinases and phosphatases, themselves under the intricate control of calcium fluxes. It is therefore no surprise that cadmium will exert effects on the activity of transcription factors, the activation of proto-oncogenes, and thereby on gene expression (Figure 20.8i and i ). 

It is SREBPs which coordinate the expression of HMG CoA reductase and cell surface receptors for LDL. Cholesterol is an essential component of membranes so if delivery of cholesterol to the cell is limited by low concentrations of LDL-cholesterol, the expression of the genes for both the LDL receptor and HMG CoA reductase are up-regulated allowing the cell to extract as much as possible form the circulation and also to synthesize cholesterol, thus there is an inverse relationship between plasma LDL-cholesterol concentration and HMG CoA reductase activity. 

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