Eukaryotic promoter
The eukaryotic promoter is part of the genetic information in living organisms with a cell nucleus ( eukaryotes ). It is that section of the DNA which lies directly before the start of transcription of the respective gene and contains information about when and in which cell type the respective gene is to be expressed . Compared to the promoter of other living beings, the eukaryotic promoter is much more complicated.
structure
The eukaryotic promoter is divided into three sections: closest to the start of transcription of the gene is the core promoter , followed by the proximal promoter (against the reading direction) and further away the enhancers and possible locus control regions . Not all sections are found in all eukaryotic genes.
Core promoter
The core promoter extends maximally between position -37 to +32, if +1 the transcription start of the gene is determined. In the core promoter there is often a TATA box and often a downstream promoter element . Sometimes there are two TATA boxes or a BRE element for the TATA box .
Proximal promoter
The proximal promoter is located between positions −50 and −200. It can contain a CAAT box , a GC box or a CpG island . The proximal promoter also contains the binding sequences for transcription factors , which in turn are complexed with coactivators or corepressors .
Enhancer
Enhancer and silencer regions are known from most genes of higher eukaryotes. Like the promoters, they belong to the cis elements . Due to the supercoiling of eukaryotic DNA, enhancers do not have to be located close to the start of transcription. Distances up to 100 kbp are known. Enhancers contain additional binding sites for transcription factors.
Locus Control Regions (LCR)
LCR are many thousands of base pairs away from the start of transcription and consist of DNase I -sensitive regions. Supercoiling also plays a role here. There are 20 known gene families in humans, the expression of which is controlled via LCR.
Individual evidence
- ↑ Jennifer EF Butler, James T. Kadonaga: The RNA polymerase II core promoter: a key component in the regulation of gene expression . In: Genes & Development . 16, No. 20, October 15, 2002, pp. 2583-2592. doi : 10.1101 / gad.1026202 . PMID 12381658 .
- ↑ Jochen Graw, Wolfgang Hennig : Genetics. 4th completely revised edition. Springer-Verlag, Berlin et al. 2006, ISBN 3-540-24096-9 , pp. 320–329.
- ↑ reactome: Generic Transcription Pathway ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. doi : 10.3180 / REACT_12627.1
