CCAAT box

Two important cis-acting elements in the ALDH2 promoter have been studied. A site located from 79 to 116 bp upstream of the ATG initiating translation is bound by nuclear factor(s) present in all cells tested the CCAAT box in this region is important for transcriptional activity, and appears to be bound primarily by the transcription factor NF-Y/CP1 [46]. There is a site, approximately 300 bp upstream of the ATG, at which HNF-4 and retinoid X receptors can bind, as can the apolipoproteins regulatory protein (ARP-1) [47, 48]. Transcription from this promoter can be activated by HNF-4 and RXRs [47, 48]. 

Wenkel, S., Turck, F., Singer, K., Gissot, L., Le Gourrierec, J., Samach, A. and Coupland, G. (2006). CONSTANS and the CCAAT box binding complex share a functionally important domain and interact to regulate flowering of Arabidopsis. Plant Cell 18, 2971-84. 

A CCAAT box (around -75) that binds a transcription fartor NF-1... 

The tasks of transcriptional and translational signal recognition involve the prediction of promoters and sites that function in the initiation and termination of transcription and translation. Bacterial promoter sites, specifically the Escherichia coli RNA polymerase promoter site, are now very well characterized. The main problem is that the two conserved regions of the bacterial promoter, the -10 and -35 regions, are separated from each other by 15 to 21 bases, making the detection of the entire promoter as a single pattern difficult. Eukaryotic promoters are less well characterized than their bacterial equivalents. The major elements are the CCAAT box, GC box, TATA box and cap site. 

The CCAAT box (sometimes referred to as a CAAT or CAT box) is a distinct pattern of nucleotides with a GGNCAATCT sequence that occurs 50-130 bases upstream of the initial transcription site. The CCAAT box signals the binding site for the RNA transcription factor and is typically accompanied by a conserved sequence. Genes that have this element seem to require it for transcription in sufficient quantities. 

CCAAT box/ enhancer binding protein complement C3 fragment d complement C4 fragment d cornu ammonis... 

Hexokinase is an enzyme that is mentioned at an early point in most biochemistry courses, since this enzyme is required for the first step in the body s utilization of glucose. The promoter for the hexokinase gene is shown here. This promoter consists of about 160 base pairs, and contains a TATA box (AATAA underlined), a CCAAT box [also underlined), and a short sequence of DNA that is regulated by a hormone. The hormone-regulated sequence is CCACGTCA (underlined). This short sequence of DNA is one of many types of "response elements" that occur in the genome. Specifically, CCACGTCA is called the cyclic AMP response element, for reasons that are explained later. This response element occurs in the hexokinase promoter, just a few nucleotides beyond the CCAAT box (Osawa rf a., 1996) ... 

CCAAT box. (CAAT box CAT box). A sequence found in the 5 flanking region of certain genes which is necessary for efficient expression. 

To date, all human drug-related transporters examined lack a functional TATA box in their promoter sequences. Instead, their promoters feature a consensus CCAAT box and two GC box-like sequences as first documented in ABCBl [4]. Figure 15.1 gives a schematic overview of the ABCBl promoter elements that support its basal expression. 

The MRP2 promoter, which lacks GC-rich sequences, possesses a putative CCAAT box that interacts in vitro with YB-1 rather than NE-Y. In summary, constitutive expression of ABC drug transporters is conferred mainly by SP-1 binding to GC-rich sequences and by NE-Y binding to an inverted CCAAT box [6, 7]. 

Rangan, V. S., Oskouian, B. and Smith, S., Identification of an inverted CCAAT box motif in the fatty-acid synthase gene as an essential element for modification of transcriptional regulation by cAMP, J Biol Chem 271 (1996) 2307-2312. 

Gao, X.H., P.P. Dwivedi, S. Choe, F. Alba, H.A. Morris, J.L. Omdahl et al. (2002). Basal and parathyroid hormone induced expression of the human 25-hydroxyvitamin D la-hydroxylase gene promoter in kidney AOK-B50 cells Role of Spl, Ets and CCAAT box protein binding sites. Int. J. Biochem. Cell Biol. 34, 921-930. 

Eukaryotes have different RNA polymerase-binding promoter sequences than prokaryotes. The TATA consensus sequence of the eukaryotic promoter region is located 25 to 35 bp upstream from the transcription start site (Fig. 6.13). The low activity of basal promoters is greatly inaeased by the presence of other elements located upstream from the promoter called upstream regulatory elements. These elements are located 40 to 200 bp upstream of the promoter sequence and include the SP1 box, the CCAAT box, and the hormone response elements. Transcription from many eukaryotic promoters can be stimulated by control elements, called enhancers, located many thousands of base pairs away from the transcription start site and usually 100 to 200 bp in length. 

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