Conserved sequence motifs upstream from the co-ordinately expressed vitellogenin and apo VLDLII genes of chicken

Abstract

The vitellogenin and apoVLDLII yolk protein genes of chicken are transcribed in the liver upon estrogenization. To get information on putative regulatory elements, we compared more than 2 kb of their 5' flanking DNA sequences. Common sequence motifs were found in regions exhibiting estrogen-induced changes in chromatin structure. Stretches of alternating pyrimidines and purines of about 30-nucleotides long are present at roughly similar positions. A distinct box of sequence homology in the chicken genes also appears to be present at a similar position in front of the vitellogenin genes of Xenopus laevis, but is absent from the estrogen-responsive egg-white protein genes expressed in the oviduct. In front of the vitellogenin (position -595) and the VLDLII gene (position -548), a DNA element of about 300 base-pairs was found, which possesses structural characteristics of a mobile genetic element and bears homology to the transposon-like Vi element of Xenopus laevis.

Two functional estrogen response elements are located upstream of the major chicken vitellogenin gene.

“…We cloned the -1133/-69 fragment from the 5'-flanking region of the VTGII gene (3,44) in both orientations immediately upstream of the TK promoter in pTK.CAT (Fig. 1).…”

“…In the present paper, we report detailed functional analysis of estrogen response elements (EREs) associated with a chicken yolk protein gene. We examined 1.1 kilobases (kb) of 5'-flanking DNA (3,44) from the major vitellogenin gene (VTGII) and identified two functional EREs which share homology with the EREs described for the frog vitellogenin genes (25,38). For the chicken VTGII gene, these EREs map to regions that we (3)(4)(5) and others (31,37) previously identified as being restructured in vivo at the chromatin level in response to estradiol.…”

“…This plasmid i with the herpes simplex virus thymi moter and start site (-105 to +51) fu region, which in turn is fused to the lation signals from simian virus 40. T enlylation cassette was taken from pS the TK promoter was derived from scanning mutant of McKnight and K ately upstream of the TK promoter ai sites (HindIII, Sal, and BamHI) I parent pVTG/TK/CAT plasmids us( constructed from pTK.CAT as follo fragment located immediately upstre moter was isolated from plasmid pN ment extends from the EcoRI site at at -1133; the latter is the left end of t from which the fragment was origina cleotide positions are numbered rela site [44].) The EcoRI ends were fille fragment of Poll; then, HindIII linker ligase, and the fragment was cloned i the HindIII site of pTK.CAT.…”

Tissue-specific and steroid-dependent interaction of transcription factors with the oestrogen-inducible apoVLDL II promoter in vivo.

“…All constructs were analysed by DNA sequencing (Sanger et al, 1977). Other M 13 probes used were described by Van het Schip et al (1986). Probes used for genomic blots are indicated in Figure 1.…”

“…We have been studying the promoter of the oestrogeninducible apoVLDL H gene (Van het Schip et al, 1983, 1986) encoding the apo very low density lipoprotein II of chicken. The rapid activation of the gene in the expressing liver (Wiscocil et al, 1980) is accompanied by the simultaneous appearance of DNase I-hypersensitive sites within the 300-bp upstream region, indicating changes in protein -DNA interactions (Kok et al, 1985).…”