scholarly journals Reconstitution of cell-type-specific transcription of the rat prolactin gene in vitro.

1987 ◽  
Vol 7 (10) ◽  
pp. 3402-3408 ◽  
Author(s):  
Z D Cao ◽  
E A Barron ◽  
A J Carillo ◽  
Z D Sharp
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Expression System ◽  
In Vitro Transcription ◽  
Gh3 Cells ◽  
Nuclear Extracts ◽  
Prolactin Gene ◽  
Flanking Region ◽  
Imperfect Palindrome

We present evidence for the existence of prolactin upstream factor 1 (PUF-1) in rat pituitary-derived cells and demonstrate its interaction with a symmetrical DNA element located in the 5' flanking region of the gene. An in vitro expression system developed from pituitary-derived GH3 cells was used to determine that 420 base pairs (bp) of 5' flanking DNA was sufficient for cell-specific, accurate, and efficient RNA polymerase II transcription of the rat prolactin gene. Reconstitution of in vitro transcription with pituitary and nonpituitary nuclear extracts suggested that the presence of GH3 cell-specific factors mediated the activation of prolactin gene expression. We also demonstrated that a functionally stable transcription complex assembled on the prolactin promoter. Using DNase I protection procedures, we have identified the DNA-protein binding area in the prolactin 5' flanking region. GH3 nuclear extracts contain a cell-specific protein (PUF-I) that binds to a 28-bp region (-63 to -36)which contains an 18-bp imperfect palindrome (-63 to -46). The role that the interaction between PUF-I and the imperfect palindrome plays in in vitro pituitary-specific prolactin gene expression is discussed.

Reconstitution of cell-type-specific transcription of the rat prolactin gene in vitro

1987 ◽  
Vol 7 (10) ◽  
pp. 3402-3408
Author(s):  
Z D Cao ◽  
E A Barron ◽  
A J Carillo ◽  
Z D Sharp
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Expression System ◽  
In Vitro Transcription ◽  
Gh3 Cells ◽  
Nuclear Extracts ◽  
Prolactin Gene ◽  
Flanking Region ◽  
Imperfect Palindrome

We present evidence for the existence of prolactin upstream factor 1 (PUF-1) in rat pituitary-derived cells and demonstrate its interaction with a symmetrical DNA element located in the 5' flanking region of the gene. An in vitro expression system developed from pituitary-derived GH3 cells was used to determine that 420 base pairs (bp) of 5' flanking DNA was sufficient for cell-specific, accurate, and efficient RNA polymerase II transcription of the rat prolactin gene. Reconstitution of in vitro transcription with pituitary and nonpituitary nuclear extracts suggested that the presence of GH3 cell-specific factors mediated the activation of prolactin gene expression. We also demonstrated that a functionally stable transcription complex assembled on the prolactin promoter. Using DNase I protection procedures, we have identified the DNA-protein binding area in the prolactin 5' flanking region. GH3 nuclear extracts contain a cell-specific protein (PUF-I) that binds to a 28-bp region (-63 to -36)which contains an 18-bp imperfect palindrome (-63 to -46). The role that the interaction between PUF-I and the imperfect palindrome plays in in vitro pituitary-specific prolactin gene expression is discussed.

scholarly journals Transcriptional and posttranscriptional regulation of the rat prolactin gene by calcium.

1990 ◽  
Vol 10 (2) ◽  
pp. 442-448 ◽  
Author(s):  
G M Preston ◽  
W M Billis ◽  
B A White
Keyword(s):  
Posttranscriptional Regulation ◽  
In Vitro Transcription ◽  
Gh3 Cells ◽  
Mrna Levels ◽  
Nuclear Extracts ◽  
Nuclear Site ◽  
Gene Treatment ◽  
Prolactin Gene ◽  
Prolactin Mrna

The rat prolactin gene is expressed at a high basal level in the pituitary tumor GH3 cell line. Culturing GH3 cells in a low-Ca2+, serum-free medium (SFM) depresses prolactin mRNA levels, and subsequent addition of Ca2+ to the SFM results in a specific, gradual, and sustained increase in prolactin mRNA levels. We have now examined whether the observed increase in prolactin mRNA levels can be attributed solely to an increase in the transcriptional rate of the prolactin gene. Treatment of GH3 cells in SFM with 0.4 mM CaCl2 for 24 to 48 h increased cytoplasmic prolactin mRNA levels by 5- to 10-fold, whereas the transcriptional rate of the prolactin gene was increased by less than twofold over values for SFM controls. Prolactin mRNA levels increased progressively during the 24-h period after Ca2+ addition, whereas prolactin gene transcription never exceeded a twofold increase over values for SFM controls. The activities of nuclear extracts from control and Ca2(+)-induced cells were examined in an in vitro transcription assay. The two extracts directed transcription from the prolactin promoter and the adenovirus major late promoter equally well. Cycloheximide had no effect on the ability of Ca2+ to increase or maintain prolactin mRNA levels. In dactinomycin mRNA clearance experiments, prolactin mRNA was cleared at the same rate in the absence and presence of Ca2+. These results demonstrate that although Ca2+ has a small effect on the transcriptional rate of the prolactin gene, Ca2+ produces a significant increase in prolactin mRNA levels by acting at a posttranscriptional site(s). Furthermore, Ca(2+) appears to increase prolactin mRNA levels by posttranslational modification of a stable protein, probably at a nuclear site.

Transcriptional and posttranscriptional regulation of the rat prolactin gene by calcium

1990 ◽  
Vol 10 (2) ◽  
pp. 442-448
Author(s):  
G M Preston ◽  
W M Billis ◽  
B A White
Keyword(s):  
Posttranscriptional Regulation ◽  
In Vitro Transcription ◽  
Gh3 Cells ◽  
Mrna Levels ◽  
Nuclear Extracts ◽  
Nuclear Site ◽  
Gene Treatment ◽  
Prolactin Gene ◽  
Prolactin Mrna

The rat prolactin gene is expressed at a high basal level in the pituitary tumor GH3 cell line. Culturing GH3 cells in a low-Ca2+, serum-free medium (SFM) depresses prolactin mRNA levels, and subsequent addition of Ca2+ to the SFM results in a specific, gradual, and sustained increase in prolactin mRNA levels. We have now examined whether the observed increase in prolactin mRNA levels can be attributed solely to an increase in the transcriptional rate of the prolactin gene. Treatment of GH3 cells in SFM with 0.4 mM CaCl2 for 24 to 48 h increased cytoplasmic prolactin mRNA levels by 5- to 10-fold, whereas the transcriptional rate of the prolactin gene was increased by less than twofold over values for SFM controls. Prolactin mRNA levels increased progressively during the 24-h period after Ca2+ addition, whereas prolactin gene transcription never exceeded a twofold increase over values for SFM controls. The activities of nuclear extracts from control and Ca2(+)-induced cells were examined in an in vitro transcription assay. The two extracts directed transcription from the prolactin promoter and the adenovirus major late promoter equally well. Cycloheximide had no effect on the ability of Ca2+ to increase or maintain prolactin mRNA levels. In dactinomycin mRNA clearance experiments, prolactin mRNA was cleared at the same rate in the absence and presence of Ca2+. These results demonstrate that although Ca2+ has a small effect on the transcriptional rate of the prolactin gene, Ca2+ produces a significant increase in prolactin mRNA levels by acting at a posttranscriptional site(s). Furthermore, Ca(2+) appears to increase prolactin mRNA levels by posttranslational modification of a stable protein, probably at a nuclear site.

Sequence requirements for premature transcription arrest within the first intron of the mouse c-fos gene

1991 ◽  
Vol 11 (5) ◽  
pp. 2832-2841
Author(s):  
N Mechti ◽  
M Piechaczyk ◽  
J M Blanchard ◽  
P Jeanteur ◽  
B Lebleu
Keyword(s):  
Rna Polymerase Ii ◽  
In Vitro Transcription ◽  
Rna Transcripts ◽  
First Intron ◽  
Nuclear Extracts ◽  
Intron 1 ◽  
A Cell ◽  
Sequence Requirements

A strong block to the elongation of nascent RNA transcripts by RNA polymerase II occurs in the 5' part of the mammalian c-fos proto-oncogene. In addition to the control of initiation, this mechanism contributes to transcriptional regulation of the gene. In vitro transcription experiments using nuclear extracts and purified transcription templates allowed us to map a unique arrest site within the mouse first intron 385 nucleotides downstream from the promoter. This position is in keeping with that estimated from nuclear run-on assays performed with short DNA probes and thus suggests that it corresponds to the actual block in vivo. Moreover, we have shown that neither the c-fos promoter nor upstream sequences are absolute requirements for an efficient transcription arrest both in vivo and in vitro. Finally, we have characterized a 103-nucleotide-long intron 1 motif comprising the arrest site and sufficient for obtaining the block in a cell-free transcription assay.

scholarly journals Prolactin upstream factor I mediates cell-specific transcription.

1988 ◽  
Vol 8 (12) ◽  
pp. 5432-5438 ◽  
Author(s):  
Z D Cao ◽  
E A Barron ◽  
Z D Sharp
Keyword(s):  
Gene Transcription ◽  
Rna Synthesis ◽  
Transcriptional Activity ◽  
In Vitro Transcription ◽  
Gh3 Cells ◽  
In Vitro Mutagenesis ◽  
Pituitary Cells ◽  
Factor I ◽  
Prolactin Gene

DNA sequence-specific chromatography was used to purify prolactin upstream factor I (PUF-I) approximately 10,000- to 20,000-fold from rat GH3 cells. The purified transcription factor reconstituted enhanced pituitary-specific prolactin RNA synthesis in nonpituitary in vitro transcription assays. In vitro mutagenesis demonstrated that the capacity to stimulate prolactin gene transcription was directly correlated with PUF-I binding to an A+T-rich region located from -63 to -36 in the prolactin 5'-flanking DNA. We propose that PUF-I is a critical modulator of transcriptional activity in pituitary cells and has a central role in the stimulation of prolactin gene transcription in the mammalian pituitary lactotroph.

Identification of two transcription factors that bind to specific elements in the promoter of the adenovirus early-region 4

1988 ◽  
Vol 8 (3) ◽  
pp. 1290-1300
Author(s):  
H Watanabe ◽  
T Imai ◽  
P A Sharp ◽  
H Handa
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
In Vitro Transcription ◽  
Initiation Site ◽  
Base Pairs ◽  
Early Region ◽  
Dnase I Footprinting ◽  
Nuclear Extracts ◽  
Early Region 4

Two kinds of trans-acting factors that regulate transcription from the promoter of the adenovirus early-region 4 (E4) have been identified by reconstituting nuclear extracts of HeLa cells. They were designated E4TF1 and E4TF3 for E4 transcription factors. These factors were responsible for efficient and accurate transcription in vitro from the E4 promoter, as were another transcription factor, designated E4TF2, and a crude fraction containing endogenous RNA polymerase II. E4TF1 stimulated transcription from the E4 promoter but not from the major late promoter or the E4 mutant promoter lacking the E4TF1-binding site. Footprint analysis of E4TF1 revealed that it binds to a specific region, residing between 132 and 152 base pairs upstream from the initiation site of the E4 mRNA. E4TF3 also regulated transcription from the E4 promoter. E4TF3 protected four ca. 20-base-pair regions in a DNase I footprinting assay. They were located around 40, 160, 230, and 260 base pairs upstream from the initiation site of E4 mRNA. Specific inhibition of E4 transcription was observed by addition of DNA fragments covering one of the E4TF1- and E4TF3-binding sites to in vitro transcription assays. These results suggest that both E4TF1 and E4TF3 regulate E4 transcription by binding to the specific upstream elements in the E4 promoter. These factors may be involved in the E1A transactivation of E4 transcription.

Dual functions of a cis-acting element within the rat prolactin gene promoter

1989 ◽  
Vol 9 (2) ◽  
pp. 817-819
Author(s):  
E A Barron ◽  
Z Cao ◽  
B G Schneider ◽  
E Kraig ◽  
A J Carrillo ◽  
...  
Keyword(s):  
Promoter Region ◽  
Gene Promoter ◽  
In Vitro Transcription ◽  
Cis Acting ◽  
Transcription System ◽  
Prolactin Gene ◽  
Imperfect Palindrome ◽  
Dual Functions ◽  
Symmetrical Sequence

Within the promoter region of the rat prolactin gene lies a TA-rich imperfect palindrome. The possible functions of the 18-base-pair symmetrical sequence were investigated by using an in vitro transcription system. Prolactin templates with and without the palindrome were transcriptionally assayed in both pituitary and nonpituitary extracts. Our results indicated that the palindromic sequence has at least two functions in the regulation of prolactin transcription.

scholarly journals Adenovirus E1B 55K Represses p53 Activation In Vitro

1998 ◽  
Vol 72 (4) ◽  
pp. 3146-3154 ◽  
Author(s):  
Michelle E. D. Martin ◽  
Arnold J. Berk
Keyword(s):  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Expression System ◽  
Gel Filtration ◽  
Velocity Sedimentation ◽  
Nuclear Extracts ◽  
P53 Activation ◽  
Adenovirus E1b

ABSTRACT Adenovirus E1B 55K protein cooperates with E1A gene products to induce cell transformation. E1B 55K mediates its effects by binding to and inhibiting the transcriptional activation and growth-suppression functions of the tumor suppressor p53. Previous studies in vivo have suggested that E1B 55K has an active role in repressing p53 transcriptional activation and that this repression function is directed to specific promoters through E1B 55K’s interaction with DNA-bound p53. Flag-tagged E1B 55K (e55K) was expressed with the baculovirus expression system and immunopurified. Gel filtration, velocity sedimentation centrifugation, and glutaraldehyde cross-linking indicated that e55K is a dimer with a nonglobular conformation. e55K bound directly to purified p53, causing an ∼10-fold increase in p53 affinity for tandem binding sites. Using in vitro transcription assays reconstituted with purified p53, e55K, and HeLa cell nuclear extracts, we found that e55K specifically repressed p53 activation. These results demonstrate that as postulated from earlier transient expression experiments, E1B 55K is a specific repressor of transcription from a promoter with bound p53. Since HeLa nuclear extracts contain little detectable histone protein, E1B 55K probably represses transcription through direct or indirect interactions with the RNA polymerase II transcription machinery.

scholarly journals Identification of two transcription factors that bind to specific elements in the promoter of the adenovirus early-region 4.

1988 ◽  
Vol 8 (3) ◽  
pp. 1290-1300 ◽  
Author(s):  
H Watanabe ◽  
T Imai ◽  
P A Sharp ◽  
H Handa
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
In Vitro Transcription ◽  
Initiation Site ◽  
Base Pairs ◽  
Early Region ◽  
Dnase I Footprinting ◽  
Nuclear Extracts ◽  
Early Region 4

Two kinds of trans-acting factors that regulate transcription from the promoter of the adenovirus early-region 4 (E4) have been identified by reconstituting nuclear extracts of HeLa cells. They were designated E4TF1 and E4TF3 for E4 transcription factors. These factors were responsible for efficient and accurate transcription in vitro from the E4 promoter, as were another transcription factor, designated E4TF2, and a crude fraction containing endogenous RNA polymerase II. E4TF1 stimulated transcription from the E4 promoter but not from the major late promoter or the E4 mutant promoter lacking the E4TF1-binding site. Footprint analysis of E4TF1 revealed that it binds to a specific region, residing between 132 and 152 base pairs upstream from the initiation site of the E4 mRNA. E4TF3 also regulated transcription from the E4 promoter. E4TF3 protected four ca. 20-base-pair regions in a DNase I footprinting assay. They were located around 40, 160, 230, and 260 base pairs upstream from the initiation site of E4 mRNA. Specific inhibition of E4 transcription was observed by addition of DNA fragments covering one of the E4TF1- and E4TF3-binding sites to in vitro transcription assays. These results suggest that both E4TF1 and E4TF3 regulate E4 transcription by binding to the specific upstream elements in the E4 promoter. These factors may be involved in the E1A transactivation of E4 transcription.

Prolactin upstream factor I mediates cell-specific transcription

1988 ◽  
Vol 8 (12) ◽  
pp. 5432-5438
Author(s):  
Z D Cao ◽  
E A Barron ◽  
Z D Sharp
Keyword(s):  
Gene Transcription ◽  
Rna Synthesis ◽  
Transcriptional Activity ◽  
In Vitro Transcription ◽  
Gh3 Cells ◽  
In Vitro Mutagenesis ◽  
Pituitary Cells ◽  
Factor I ◽  
Prolactin Gene

DNA sequence-specific chromatography was used to purify prolactin upstream factor I (PUF-I) approximately 10,000- to 20,000-fold from rat GH3 cells. The purified transcription factor reconstituted enhanced pituitary-specific prolactin RNA synthesis in nonpituitary in vitro transcription assays. In vitro mutagenesis demonstrated that the capacity to stimulate prolactin gene transcription was directly correlated with PUF-I binding to an A+T-rich region located from -63 to -36 in the prolactin 5'-flanking DNA. We propose that PUF-I is a critical modulator of transcriptional activity in pituitary cells and has a central role in the stimulation of prolactin gene transcription in the mammalian pituitary lactotroph.

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