Transcription factor MSY-1 regulates expression of the murine growth hormone receptor gene.
Previous studies identified and partially characterized a 42-base pair regulatory element in the 5'-flanking region of the L1 transcript of the murine growth hormone (GH) receptor gene that interacted with both double- and single-stranded DNA-binding proteins. We present evidence that the double-stranded DNA-binding protein is NF-Y, a CCAAT box-binding protein. Experiments with a dominant negative form of NF-Y indicate that NF-Y does not play a direct role in regulating the activity of the FP42 element. A cDNA clone that specifically interacts with the upper (coding) strand of the regulatory element was isolated by screening a cDNA expression library using the Southwestern technique. DNA sequencing, electrophoretic mobility shift assay, Southwestern blot analysis, and supershift EMSA confirm the identity of the single-stranded binding protein to be MSY-1, a DNA-binding protein that is evolutionary conserved from prokaryotes to eukaryotes. Mapping of single-stranded DNA configurations reveals that MSY-1 can facilitate the formation of single-stranded DNA regions in the GH receptor 5'-flanking region. Transient transfection experiments support the role of MSY-1 as a repressor of GH receptor gene activation. Southwestern blot analysis indicates that the levels of nuclear MSY-1 are decreased in the livers of pregnant mice, suggesting a role for MSY-1 in the increased expression of the GH receptor during pregnancy.
Schwartzbauer
G
G
Department of Pediatrics, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Yu
J H
JH
Cheng
H
H
Menon
R K
RK
D000818:Animals; D001483:Base Sequence; D018983:DNA Footprinting; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D008099:Liver / Q000378:metabolism*; D051379:Mice; D016297:Mutagenesis, Site-Directed; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011986:Receptors, Somatotropin / Q000096:biosynthesis / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D011986:Receptors, Somatotropin; D011994:Recombinant Proteins; C541744:Ybx1 protein, mouse; D014157:Transcription Factors