Transcriptional feedback

Schwartz E, Buhrke T, Gerischer U, Friedrich B. 1999. Positive transcriptional feedback controls hydrogenase expression in Alcaligenes eutrophus H16. J Bacteriol 181 5684-92. 

Takahashi That is a good point. The transcriptional feedback loop has been selected because of all the downstream outputs that it controls. It would be hard to do this with a post-transcriptional mechanism. 

Modulation of Nrf2/ARE Signaling Transactivation and Transcriptional Feedback 416... 

MODULATION OF NRF2/ARE SIGNALING TRANSACTIVATION AND TRANSCRIPTIONAL FEEDBACK... 

Kaufer, D., Friedman, A., Seidman, S., Soreq, H. (1999). Anticholinesterase induce multigenic transcriptional feedback response suppressing cholinergic neurotransmisison. Chem. Biol. Interact. 199-20 349-60. 

Scarlato V, Prugnola A, Arico B., et al. (1990) Positive transcriptional feedback at the bvg locus controls expression of virulence factors in Bordefella pertussis. In Proc. Natl. Acad. Sci. USA 87 6753-6757. 

Picker, A., S. Scholpp, H. Bohli, H. Takeda and M. Brand. A novel positive transcriptional feedback loop in midbrain-hindbrain boundary development is revealed through analysis of the zebrafish pax2.1 promoter in transgenic lines. Development 129 3227-3239, 2002. 

Zordan RE, Galgoczy DJ, Johnson AD (2006) Epigenetic properties of white-opaque switching in Candida albicans are based on a self-sustaining transcriptional feedback loop. Proc Natl Acad Sci USA 103 12807-12812... 

From above results, it suggests that retinoids such as retinal (16), retinol (vitamin A, 18) and retinoic acid (20), and carotenoids such as P-carotene (2), P-cryptoxanthin (5) and lycopene (3) could regulate the expression of P,P-carotene 15,15 -monooxygenase using a transcriptional feedback mechanism through their interaction with the members of the retinoic acid (20) receptor (RAR) family (Figure 5) [11]. 

In all types of mammalian cells, the molecular mechanism underlying circadian clock function is based upon interconnected transcription/translation feedback loops [2] (Fig. 2). Two proteins that function as transcriptional... 

At its most fundamental level, the circadian cycle rests on the influence of so-called clock genes . These genes have been studied most extensively in insects but they have also been found in humans. Their protein products enter the cell nucleus and regulate their own transcription. This feedback process is linked to exposure to light and so it is not surprising that visual inputs are important for maintenance of circadian rhythms. However, it is not the reception of specific visual information, transmitted in the optic nerve to the lateral geniculate nucleus (LGN) and visual cortex (i.e. visual discrimination), that is responsible for the rhythm but the more simple, almost subconscious, reception of light. 

Fig. 3.13. A simplified version of a genetic construct which requires not only a reading frame to generate the m-RNA and then the protein but requires a binding region for the polymerase machinery and an instruction region for the binding of a transcription factor, both of which must be bound in appropriate form before reading can occur. The form of the transcription factor which may interact by feedback with an element, M, can be adjusted (by [M]) to stop reading. The whole is necessary for cell operations not just for that of DNA reactions.

The DNA/RNA machinery operates to produce the proteins including the above pumps and catalysts under feedback control from simple metabolites and ions through their binding to transcription factors. 

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