scholarly journals Two Promoters Mediate Transcription from the Human LHX3 Gene: Involvement of Nuclear Factor I and Specificity Protein 1

Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 324-337 ◽  
Author(s):  
Benjamin C. Yaden ◽  
Marin Garcia ◽  
Timothy P. L. Smith ◽  
Simon J. Rhodes

The LHX3 transcription factor is required for pituitary and nervous system development in mammals. Mutations in the human gene are associated with hormone-deficiency diseases. The gene generates two mRNAs, hLHX3a and hLHX3b, which encode three proteins with different properties. Here, the cis elements and trans-acting factors that regulate the basal transcription of the two mRNAs are characterized. A comparative approach was taken featuring analysis of seven mammalian Lhx3 genes, with a focus on the human gene. Two conserved, TATA-less, GC-rich promoters that are used to transcribe the mRNAs precede exons 1a and 1b of hLHX3. Transcription start sites were mapped for both promoters. Deletion experiments showed most activity for reporter genes containing the basal promoters in the context of −2.0 kb of hLHX3a and 1.8 kb of intron 1a (hLHX3b). Transfection, site-directed mutation, electrophoretic mobility shift, Southwestern blot, and chromatin immunoprecipitation approaches were used to characterize the interaction of transcription factors with conserved elements in the promoters. Specificity protein 1 is a regulator of both promoters through interaction with GC boxes. In addition, a distal element within intron 1a that is recognized by nuclear factor I is critical for hLHX3b promoter function. We conclude that dual promoters allow regulated production of two hLHX3 mRNAs.

1990 ◽  
Vol 10 (3) ◽  
pp. 1041-1048 ◽  
Author(s):  
N Goyal ◽  
J Knox ◽  
R M Gronostajski

Nuclear factor I (NFI) is a group of related site-specific DNA-binding proteins that function in adenovirus DNA replication and cellular RNA metabolism. We have measured both the levels and forms of NFI that interact with a well-characterized 26-base-pair NFI-binding site. Five different NFI-DNA complexes were seen in HeLa nuclear extracts by using a gel mobility shift (GMS) assay. In addition, at least six forms of NFI were shown to cross-link directly to DNA by using a UV cross-linking assay. The distinct GMS complexes detected were composed of different subspecies of NFI polypeptides as assayed by UV cross-linking. Different murine cell lines possessed varying levels and forms of NFI binding activity, as judged by nitrocellulose filter binding and GMS assays. The growth state of NIH 3T3 cells affected both the types of NFI-DNA complexes seen in a GMS assay and the forms of the protein detected by UV cross-linking.


1991 ◽  
Vol 11 (8) ◽  
pp. 4065-4073 ◽  
Author(s):  
M C Nehls ◽  
R A Rippe ◽  
L Veloz ◽  
D A Brenner

The collagen alpha 1(I) promoter, which is efficiently transcribed in NIH 3T3 fibroblasts, contains four binding sites for trans-acting factors, as demonstrated by DNase I protection assays (D. A. Brenner, R. A. Rippe, and L. Veloz, Nucleic Acids Res. 17:6055-6064, 1989). This study characterizes the DNA-binding proteins that interact with the two proximal footprinted regions, both of which contain a reverse CCAAT box and a G + C-rich 12-bp direct repeat. Analysis by DNase I protection assays, mobility shift assays, competition with specific oligonucleotides, binding with recombinant proteins, and reactions with specific antisera showed that the transcriptional factors nuclear factor I (NF-I) and Sp1 bind to these two footprinted regions. Because of overlapping binding sites, NF-I binding and Sp1 binding appear to be mutually exclusive. Overexpression of NF-I in cotransfection experiments with the alpha 1(I) promoter in NIH 3T3 fibroblasts increased alpha 1(I) expression, while Sp1 overexpression reduced this effect, as well as basal promoter activity. The herpes simplex virus thymidine kinase promoter, which contains independent NF-I- and Sp1-binding sites, was stimulated by both factors. Therefore, expression of the collagen alpha 1(I) gene may depend on the relative activities of NF-I and Sp1.


1991 ◽  
Vol 11 (8) ◽  
pp. 4065-4073
Author(s):  
M C Nehls ◽  
R A Rippe ◽  
L Veloz ◽  
D A Brenner

The collagen alpha 1(I) promoter, which is efficiently transcribed in NIH 3T3 fibroblasts, contains four binding sites for trans-acting factors, as demonstrated by DNase I protection assays (D. A. Brenner, R. A. Rippe, and L. Veloz, Nucleic Acids Res. 17:6055-6064, 1989). This study characterizes the DNA-binding proteins that interact with the two proximal footprinted regions, both of which contain a reverse CCAAT box and a G + C-rich 12-bp direct repeat. Analysis by DNase I protection assays, mobility shift assays, competition with specific oligonucleotides, binding with recombinant proteins, and reactions with specific antisera showed that the transcriptional factors nuclear factor I (NF-I) and Sp1 bind to these two footprinted regions. Because of overlapping binding sites, NF-I binding and Sp1 binding appear to be mutually exclusive. Overexpression of NF-I in cotransfection experiments with the alpha 1(I) promoter in NIH 3T3 fibroblasts increased alpha 1(I) expression, while Sp1 overexpression reduced this effect, as well as basal promoter activity. The herpes simplex virus thymidine kinase promoter, which contains independent NF-I- and Sp1-binding sites, was stimulated by both factors. Therefore, expression of the collagen alpha 1(I) gene may depend on the relative activities of NF-I and Sp1.


1990 ◽  
Vol 10 (3) ◽  
pp. 1041-1048
Author(s):  
N Goyal ◽  
J Knox ◽  
R M Gronostajski

Nuclear factor I (NFI) is a group of related site-specific DNA-binding proteins that function in adenovirus DNA replication and cellular RNA metabolism. We have measured both the levels and forms of NFI that interact with a well-characterized 26-base-pair NFI-binding site. Five different NFI-DNA complexes were seen in HeLa nuclear extracts by using a gel mobility shift (GMS) assay. In addition, at least six forms of NFI were shown to cross-link directly to DNA by using a UV cross-linking assay. The distinct GMS complexes detected were composed of different subspecies of NFI polypeptides as assayed by UV cross-linking. Different murine cell lines possessed varying levels and forms of NFI binding activity, as judged by nitrocellulose filter binding and GMS assays. The growth state of NIH 3T3 cells affected both the types of NFI-DNA complexes seen in a GMS assay and the forms of the protein detected by UV cross-linking.


2017 ◽  
Author(s):  
Kreepa Kooblall ◽  
Mark Stevenson ◽  
Raoul Hennekam ◽  
Rajesh Thakker

1992 ◽  
Vol 267 (12) ◽  
pp. 8478-8484 ◽  
Author(s):  
H Zorbas ◽  
T Rein ◽  
A Krause ◽  
K Hoffmann ◽  
E.L. Winnacker

2011 ◽  
Vol 354 (2) ◽  
pp. 242-252 ◽  
Author(s):  
Yu-Chih Hsu ◽  
Jason Osinski ◽  
Christine E. Campbell ◽  
E. David Litwack ◽  
Dan Wang ◽  
...  

FEBS Letters ◽  
1996 ◽  
Vol 390 (1) ◽  
pp. 44-46 ◽  
Author(s):  
Shigehiro Osada ◽  
Shoko Daimon ◽  
Tsutomu Nishihara ◽  
Masayoshi Imagawa

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