Stringent response

Schmidt But they don t have a true stringent response in the way that bacteria do, so that answer is not quite right. It is not really glucose induced. 

The complex that RNA polymerase forms at the promoter site just prior to initiation. Some bacterial promoters require high NTP concentrations to initiate efficient transcription, because this represents a status report on the stores of ATP, UTP, GTP, and CTP needed for RNA synthesis. Nature has evolved a kinetic control device high initiating ATP and GTP concentrations must be present to stabilize an otherwise short-lived polymerase-promoter complex. The reader may also recall that bacterial translation is also tightly controlled, and amino acid starvation leads to ppGpp synthesis, the so-called stringent-response agent that also potently inhibits RNA polymerase. Such kinetic control ensures that NTP and amino acid concentrations are adequate before transcription and translation occur. 

As stated earlier, rRNA synthesis is usually maintained at a rate proportional to the gross rate of protein synthesis. In a normal wild-type cell, when protein synthesis is limited (e.g., by amino acid availability), M. Cashel and J. Gallant have shown that the ppGpp concentration rises rapidly from about 50 pM to 500 /uM (fig. 30.16). Concomitantly, rRNA synthesis ceases abruptly. This is part of the phenotype known as the stringent response First, amino acid deprivation or other factors that slow down protein synthesis provoke an increased rate of accumulation of ppGpp thisin turn leads to an inhibition of rRNA synthesis. 

G. J. Balzer and R. J. McLean (2002). The stringent response genes relA and spoT are important for Escherichia coli biofilms under slow-growth conditions. Can. J. Microbiol., 48, 675-680. 

G. L. Scoarughi, C. Cimmino and P. Donini (1999). Helicobacter pylori a eubacterium lacking the stringent response. J. Bactriol., 181, 552-555. 

C. Van Delden, R. Comte and A. M. Bally (2001). Stringent response activates quorum sensing and modulates cell density-dependent gene expression in Pseudomonas aeruginosa. J. Bacteriol., 183, 5376-5384. 

Evolving legal and regulatory practices and standards are becoming more stringent. Responsible Care embodies elements of preventative law that protects companies from legal liability as their performance improves. 

See also Translation Overview, Eukaryotic vs Prokaryotic Translation, Figure 27.15, Stringent Response, Posttranscriptional Processing of rRNA and tRNA... 

The very complex stringent response, which involves ribosomes in the synthesis of guanosine 5 -triphosphate-3 -diphosphate (pppGpp) imder some conditions, is dealt with further in Chapter 29 (Section C,8). The regulator pppGpp, whose concentration may rise from 50 pM to 1 mM within minutes after deprivation of amino acids, may react directly with RNA polymerase at an allosteric site to inhibit tran-... 

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