Basal transcription

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In genetics, basal transcription is a low transcription of genes in the absence of regulating activators or repressors of gene expression . In this case, the RNA polymerase binds spontaneously to a promoter in the absence of regulating activators or repressors and leads to a constitutive, usually very weak, basal transcription. Their strength depends solely on the binding affinity of the RNA polymerase for the respective promoter sequence. The type of initiation of transcription is different for eukaryotes , bacteria and archaea .

properties

Basal transcription in nature has the function of ensuring the synthesis of a minimally necessary proteome , e.g. B. to induce gene expression in a zygote or to ensure a basic set of necessary proteins in a cell.

A basal transcription is undesirable in some experiments in biotechnology, genetics or virology. When a recombinant protein that is toxic to the expression system is produced , a transgenic organism (e.g. Escherichia coli , Saccharomyces cerevisiae or cell lines ) dies before larger quantities of a toxic recombinant protein are produced. Therefore, it is an object of the vector designs , a leak (Engl. Leakiness ) of the regulation of a promoter to reduce and thus achieve an induction of the production of the toxic protein only after growing up of the organisms.

In virology, basal transcription in latent viruses is another mechanism for reactivation after virus latency, in addition to induction generated by viral and cellular proteins .

literature

  • Cornel Mülhardt: The Experimentator : Molecular Biology / Genomics , 6th edition, Springer 2009, ISBN 978-3-8274-2158-6 .
  • Karl Hans Friehs: Measures to improve the production of recombinant proteins and plasmid DNA. Bielefeld 1999 (Bielefeld University, habilitation thesis), online (PDF; 3.6 MB) .

Individual evidence

  1. ↑ James D. Watson, Tania A. Baker, Stephen P. Bell, Alexander Gann, Michael Levine, Richard M. Losick: Molecular Biology of the Gene , 5th Edition, 2004. ISBN 9780805346350 . Page 484.
  2. ↑ Shim SM, Nam HY, Lee JE, Kim JW, Han BG, Jeon JP: MicroRNAs in human lymphoblastoid cell lines. In: Crit Rev Eukaryot Gene Expr. (2012), Volume 22, Issue 3, pp. 189-96. PMID 23140160 .
  3. ^ M. Zurita, E. Reynaud, J. Aguilar-Fuentes: From the beginning: the basal transcription machinery and onset of transcription in the early animal embryo. In: Cell Mol Life Sci. (2008), Volume 65, Issue 2, pp. 212-27. PMID 17938862 .