Fallaux F J, Hoeben R C, Cramer S J, van den Wollenberg D J, Briët E, van Ormondt H, van Der Eb A J
Laboratory of Molecular Carcinogenesis, Department of Medical Biochemistry, Leiden University, The Netherlands.
Mol Cell Biol. 1996 Aug;16(8):4264-72. doi: 10.1128/MCB.16.8.4264.
Expression of the human blood-clotting factor VIII (FVIII) cDNA is hampered by the presence of sequences located in the coding region that repress transcription. We have previously identified a 305-bp fragment within the FVIII cDNA that is involved in the repression (R.C. Hoeben, F.J. Fallaux, S.J. Cramer, D.J.M. van den Wollenberg, H. van Ormondt, E. Briet, and A.J. van der Eb, Blood 85:2447-2454, 1995). Here, we show that this 305-bp region of FVIII cDNA contains sequences that resemble the yeast (Saccharomyces cerevisiae) autonomously replicating sequence consensus. Two of these DNA elements coincide with AT-rich sequences that are often found in matrix attachment regions or scaffold-attached regions. One of these elements, consisting of nucleotides 1569 to 1600 of the FVIII cDNA (nucleotide numbering is according to the system of Wood et al. (W.I. Wood, D.J. Capon, C.C. Simonsen, D.L. Eaton, J. Gitschier, D. Keyt, P.H. Seeburg, D.H. Smith, P. Hollingshead, K.L. Wion, et al., Nature [London] 312:330-337,1984), binds a nuclear factor in vitro but loses this capacity after four of its base pairs have been changed. A synthetic heptamer of this segment can repress the expression of a chloramphenicol acetyltransferase (CAT) reporter gene and also loses this capacity upon mutation. Furthermore, we demonstrate that repression by FVIII sequences can be relieved by sodium butyrate. We demonstrate that the synthetic heptamer (FVIII nucleotides 1569 to 1600), when placed upstream of the Moloney murine leukemia virus long terminal repeat promoter that drives the CAT reporter, can render the CAT reporter inducible by butyrate. This effect was absent when the same element was mutated. The stimulatory effect of butyrate could not be attributed to butyrate-responsive elements in the studied long terminal repeat promoters. Our data provide a functional characterization of the sequences that repress expression of the FVIII cDNA. These data also suggest a link between transcriptional repression by FVIII cDNA elements and the stimulatory effect of butyrate on FVIII cDNA expression.
人凝血因子VIII(FVIII)cDNA的表达受到编码区内存在的抑制转录序列的阻碍。我们之前在FVIII cDNA中鉴定出一个305 bp的片段,它参与了这种抑制作用(R.C. Hoeben、F.J. Fallaux、S.J. Cramer、D.J.M. van den Wollenberg、H. van Ormondt、E. Briet和A.J. van der Eb,《血液》85:2447 - 2454,1995)。在此,我们表明FVIII cDNA的这个305 bp区域包含与酵母(酿酒酵母)自主复制序列共有序列相似的序列。其中两个DNA元件与富含AT的序列一致,这些序列常见于基质附着区域或支架附着区域。这些元件之一,由FVIII cDNA的1569至1600个核苷酸组成(核苷酸编号依据Wood等人的系统(W.I. Wood、D.J. Capon、C.C. Simonsen、D.L. Eaton、J. Gitschier、D. Keyt、P.H. Seeburg、D.H. Smith、P. Hollingshead、K.L. Wion等人,《自然》[伦敦]312:330 - 337,1984)),在体外能结合一种核因子,但在其四个碱基对发生改变后丧失这种能力。该片段的一个合成七聚体可抑制氯霉素乙酰转移酶(CAT)报告基因的表达,并且在发生突变后也丧失这种能力。此外,我们证明FVIII序列的抑制作用可被丁酸钠解除。我们证明,当合成七聚体(FVIII核苷酸1569至1600)置于驱动CAT报告基因的莫洛尼鼠白血病病毒长末端重复启动子上游时,可使CAT报告基因对丁酸钠产生诱导反应。当相同元件发生突变时,这种效应消失。丁酸钠的刺激作用不能归因于所研究的长末端重复启动子中的丁酸钠反应元件。我们的数据提供了抑制FVIII cDNA表达的序列的功能特征。这些数据还表明FVIII cDNA元件的转录抑制与丁酸钠对FVIII cDNA表达的刺激作用之间存在联系。