Gene initiation

Hugnot, J.P., Gilgenkrantz, H., Vincent, N., Chafey, P., Morris, G.E., Monaco, A.P., Berwald-Netter, Y., Koulakoff, A., Kaplan, J.C., Kahn, A., and et al., 1992, Distal transcript of the dystrophin gene initiated from an alternative first exon and encoding a 75-kDa protein widely distributed in nonmuscle tissues, Proc Natl Acad Sci USA, 89, pp 7506-7510. 

Three principal types of promoter sequences have been identified in eukaryotic DNA. The TATA box, the most common, is prevalent in rapidly transcribed genes. Initiator promoters are found in some genes, and CpG islands are characteristic of genes transcribed at a low rate. 

Functional analysis of the TLAl gene Initiate a study of expression patterns for the TLAl gene under different irradiance conditions. 

The carcinogenic effects of carbon tetrachloride are now thought to result from the fact that the compound is converted by enzymes in the body to phosgene, which then attack cells and genes, initiating the processes by which cancer develops. 

Fig. 16.20. Production of a membrane-bound antibody (IgM) and a smaller secreted antibody (IgD) from the same gene. Initially, the lymphocytes produce a long transcript that is cleaved and polyadenylated after the second stop codon. The intron that contains the first stop codon is removed by splicing between the 5 - and 3 -splice sites. Therefore, translation ends at the second stop codon, and the protein contains a hydrophobic exon at its C-terminal end that becomes embedded in the cell membrane. After antigen stimulation, the cells produce a shorter transcript by using a different cleavage and polyadenylation site. This transcript lacks the 3 -splice site for the intron, so the intron is not removed. In this case, translation ends at the first stop codon. The IgD antibody does not contain the hydrophobic region at its C-terminus, so it is secreted from the cell.

The current model makes use of recent observations of Frallck (51), Messer, et al. (52), and Fayet Louarn (53) to construct a mechanism for the control of the Initiation of DNA synthesis. The scheme Is Illustrated In Figure 2. The dnaA gene which Is located near the origin makes a gene product (RP) which represses the transcription of the 0-RNA gene. Initiation requires 0-RNA as a primer. An antl-repressor (ARP) Is made which Inactivates RP. Experimental evidence for ARP exists (51), and there are Indications that ARP production Is related to cell envelope formation (54). In the model we have made the rate of... 

Fig. 2 - Virtual gene length distribution as found by the computer code in the complementary strands. Complementary strand means the DNA strand sequence obtained from the coding strand sequence of a given gene by the complementation rules (A T and G C). In the case of the e-globin sequence, a possible c.i.p. gene initiation codon could exist beyond the recorded one, because of an indeterminate base. If this base is not A, the c.i.p. gene length would be 222 codons. Symbols used to identify a given sequence are the same as in Fig. 1.

Initiation of transcription of the SV40 late genes is somewhat more complex than for many other genes. Initiation sites are scattered over a 200 bp stretch of DNA, without any obvious TATA sequences upstream of any of these sites. The major late initiation site which is the one furthest downstream may, however, have a TATA-like element positioned at about - 30, as determined by mutational analysis (Brady et ai, 1982). Another unusual feature of this control region is that deletion mutations including or extending to within 10 bp of prominent initiation sites often shift initiation to sites further upstream... 

The superfamily of nuclear receptor proteins is constituted by a group of transcription factors that are activated, in most cases, by hormonal ligands. For example, steroid hormones, thyroid hormones and retinoic acid bind selectively to receptors that belong to this superfamily. The hormone-receptor complexes interact with m-act-ing elements present on the promoter sequences of target genes, initiating a series of transcription events that are responsible for the hormone s effects. ... 

The nodD gene initially was thought to be a common nod gene (Downie and... 

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