Regulatory effectors

Many kinds of amino acids (eg, L-lysine, L-omithine, t-phenylalanine, L-threonine, L-tyrosine, L-valine) are accumulated by auxotrophic mutant strains (which are altered to require some growth factors such as vitamins and amino acids) (Table 6, Primary mutation) (22). In these mutants, the formation of regulatory effector(s) on the amino acid biosynthesis is genetically blocked and the concentration of the effector(s) is kept low enough to release the regulation and iaduce the overproduction of the corresponding amino acid and its accumulation outside the cells (22). 

Kleinewietfeld M, Puentes F, Borsellino G, Battistini L, Rotzschke O, Falk K. CCR6 expression defines regulatory effector/memory-like cells within the CD25(+)CD4+ T-cell subset. Blood 2005 105 2877-2886. 

In processes in other tissues, endocriue glands play the same role as the brain and ions on cyclic ATPase the regulatory effectors. 

Figure 1 Generalized model for sensing regulatory effectors by nascent mRNA leader transcripts. Transcription attenuation mechanisms have been identified in which the nascent transcript interacts with a translating 70S ribosome, a protein, an RNA molecule or a small metabolite, (a) Binding of the effector molecule promotes transcription termination, (b) Binding of the effector molecule promotes transcription readthrough (antitermination). See text for details.

During the evolution of living systems and the interdependent coevolution of new metabolic and regulatory qualities some so-called secondary products have acquired a physiological role not only for intra- or inter-specific interactions of individuals (e.g. pheromones, phytoalexins etc.) but also for the interaction between cells of the producing organisms themselves (e.g. hormones and hormone-like regulatory effectors) (Ref. 1). Thus, as indicated by the pathways of biosynthesis and metabolism, the plant hormones so far... 

In microorganisms hormone-like regulatory effectors are found scarcely. Examples, however, are ... 

Cl line width is found when IHP is added to solutions of the doubly digested hemoglobins, Hb CPA, CPB and Hb CPB, CPA. The results taken together indicate that the binding sites for "small and "big" anions overlap only partly and point to the importance of the "small" anions as separate regulatory effectors. 

Paszewski, A., and Grabski, J., 1974, Regulation of S-amino acid biosynthesis in Aspergillus nidulans. Role of cysteine and/or homocysteine as regulatory effectors. Mol. Gen. 

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