The nucleotide sequence of an 8.2-kb DNA fragment from the 5' proximal part of the chicken myb proto-oncogene spanning 1761 nucleotides upstream and 6436 nucleotides downstream from a presumed c-myb initiation codon was determined. A 3.3-kb G + C-rich region found in this sequence had also other features characterizing CpG islands, i.e. no CpG underrepresentation and lack of CpG methylation. In haematopoietic tissues c-myb mRNA synthesis starts in two major regions of the CpG island, namely 98 to 108 and 143 to 145 nucleotides upstream from the c-myb initiation codon. These two regions are in or close to the 124-bp evolutionarily conserved element located in the middle part of the CpG island. No alternative splicing of the 5' end of c-myb mRNA suggested earlier (1,2) was observed. The c-myb promoter contains neither TATA nor CAAT box-like structures at the usual positions. Instead, numerous potential Sp1 factor binding sites were found both upstream and downstream from the transcription initiation sites. Moreover, consensus v-myb protein DNA-binding sites were revealed in the promoter region and in sequences downstream from it.

• MeSH
• dinukleosidfosfáty analýza   MeSH
• endonukleasy specifické pro jednořetězcové nukleové kyseliny MeSH
• endonukleasy MeSH
• erytrocyty analýza   MeSH
• genetická transkripce * MeSH
• klonování DNA MeSH
• kur domácí MeSH
• molekulární sekvence - údaje MeSH
• myši MeSH
• orgánová specificita MeSH
• promotorové oblasti (genetika) MeSH
• protoonkogenní proteiny c-myb MeSH
• protoonkogenní proteiny genetika   MeSH
• protoonkogeny * MeSH
• restrikční mapování MeSH
• RNA čepičky genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie nukleových kyselin MeSH
• thymus analýza   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• cytidylyl-3'-5'-guanosine MeSH Prohlížeč
• dinukleosidfosfáty MeSH
• endonukleasy specifické pro jednořetězcové nukleové kyseliny MeSH
• endonukleasy MeSH
• protoonkogenní proteiny c-myb MeSH
• protoonkogenní proteiny MeSH
• RNA čepičky MeSH

The nucleotide sequence of the chicken myb proto-oncogene putative promoter region was determined and compared with the corresponding sequence of the mouse c-myb gene (1). 118 bp upstream from the initiation codon suggested by Gerondakis and Bishop (2) for the chicken c-myb protein, a 124-bp-long conserved element was found (92% identity in chicken and mouse sequences). Sequences homologous to this element were detected on Southern blots of restricted genomic DNAs from mouse, man, lizard, frog, and carp. No hybridization was observed with Drosophila, yeast, or Escherichia coli DNA. In human DNA, sequences homologous to this element were located at the 5' end of the c-myb gene, i.e. in the same position as in the chicken and mouse genes. Several lines of evidence suggest that the element is not a coding exon of a gene overlapping the c-myb gene. It may be of importance that one of the DNase I-sensitive sites and several c-myb mRNA cap sites localized recently in the mouse c-myb gene (3,4) lie within this region. It is suggested that this evolutionarily conserved element is involved in the regulation of myb proto-oncogene expression in vertebrates.

• MeSH
• biologická evoluce * MeSH
• Drosophila melanogaster MeSH
• ještěři MeSH
• kapři MeSH
• kur domácí MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• myši MeSH
• promotorové oblasti (genetika) * MeSH
• protoonkogen Mas MeSH
• protoonkogeny * MeSH
• sekvence nukleotidů * MeSH
• sekvenční homologie nukleových kyselin * MeSH
• skot MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH