A 26-Amino Acid Insertion Domain Defines a Functional Transcription Switch Motif in Pit-1β

Diamond, Scott E.; Gutierrez‐Hartmann, Arthur

doi:10.1074/jbc.271.46.28925

Cited by 24 publications

(59 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Plasmid pA3 PRL luc, firefly luciferase driven by the proximal (-425) rat (r) PRL promoter, was described previously (Conrad & Gutierrez-Hartmann 1992, Diamond & Gutierrez-Hartmann 1996, Diamond et al 1999. Plasmids pRSV HA Pit-1, pRSV HA Pit-1 , pRSV PKA and pRSV -globin, respectively driven by the RSV promoter, were described previously (Diamond & Gutierrez-Hartmann 1996, Diamond et al 1999.…”

Section: Plasmidsmentioning

confidence: 99%

“…Plasmids pRSV HA Pit-1, pRSV HA Pit-1 , pRSV PKA and pRSV -globin, respectively driven by the RSV promoter, were described previously (Diamond & Gutierrez-Hartmann 1996, Diamond et al 1999. Plasmid RSV CBP was the generous gift of Dr Chee-Gun Lee.…”

Section: Plasmidsmentioning

confidence: 99%

“…Mutant Pit-1 constructs in mammalian expression vectors were constructed by nested PCR mutagenesis of the Pit-1 transactivation domain as described previously (Diamond & Gutierrez-Hartmann 1996. The pRSV HA Pit-1 plasmid was used as a substrate for PCR mutagenesis, in which the 26 amino acid -domain was substituted with altered sequences, and a HA epitope tag was retained at the amino terminus of all of the Pit-1 constructs.…”

Section: Plasmidsmentioning

confidence: 99%

“…While Pit-1 enhances PRL and GH gene expression, Pit-1 blocks their gene expression and decreases the histone acetylation of their promoters in a manner dependent upon five hydrophobic -domain residues ( Fig. 1) (Diamond & Gutierrez-Hartmann 1996, Ferry et al 2005). Yet, in HeLa non-pituitary cells, Pit-1 activates hormone gene transcription.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Repression of the prolactin promoter: a functional consequence of the heterodimerization between Pit-1 and Pit-1 β

Sporici

Hodskins²,

Locasto³

et al. 2005

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

The POU-homeodomain transcription factor Pit-1 is required for the differentiation of the anterior pituitary cells and the expression of their hormone products. Pit-1 , an alternate splicing isoform, has diametrically different outcomes when it is expressed in different cell types. Pit-1 acts as a transcriptional repressor of prolactin (PRL) and growth hormone genes in pituitary cells, and as a transcriptional activator in non-pituitary cells. In order to explore these differences, we: (1) identified the transcriptional cofactors necessary for reconstitution of repression in non-pituitary cells; (2) tested the effect of the -domain on heterodimerization with Pit-1 and physical interaction with the co-activator CREB binding protein (CBP); and (3) determined the -domain sidechain chemistry requirements for repression. Co-expression of both Pit-1 isoforms reconstituted the repression of the PRL promoter in non-pituitary cells. The -domain allowed heterodimerization with Pit-1 but blocked physical interaction with CBP, and specific chemical properties of the -domain beyond hydrophobicity were dispensable. These data strongly suggest that Pit-1 represses hormone gene expression by heterodimerizing with Pit-1 and interfering with the assembly of the Pit-1-CBP complex required for PRL promoter activity in pituitary cells.

show abstract

Section: Plasmidsmentioning

confidence: 99%

Section: Plasmidsmentioning

confidence: 99%

Section: Plasmidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Repression of the prolactin promoter: a functional consequence of the heterodimerization between Pit-1 and Pit-1 β

Sporici

Hodskins²,

Locasto³

et al. 2005

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

show abstract

“…To map further the domain in Ets-1 responsible for binding to the Pit-1 homeodomain, we replaced overlapping 26-amino acid segments of p68 c-Ets-1 in the region from 190 to 257 with amino acids 415-440 of the BPV L-1 capsid (including the AU1 epitope) to generate a series of three block mutations that "scan" across this 68-amino acid region (BPV-1-3, Fig. 3A) (32). GST pull-down analysis was used to assess binding of these constructs to the Pit-1 homeodomain.…”

Section: Scanning Mutations Of Ets-1 Amino Acids 190 -257 Reduce Pit-mentioning

confidence: 99%

Ras Signaling and Transcriptional Synergy at a Flexible Ets-1/Pit-1 Composite DNA Element Is Defined by the Assembly of Selective Activation Domains

Duval

Jean

Gutierrez‐Hartmann

2003

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Pit-1 and Ets-1 binding to a composite element synergistically activates and targets Ras-mitogen-activated protein kinase signaling to the rat prolactin promoter. These transcriptional responses appear to depend on three molecular features: organization of the Ets-1/Pit-1 composite element, physical interaction of these two factors via the Pit-1 homeodomain (amino acids 199 -291) and the Ets-1 regulatory III domain (amino acids 190 -257), and assembly of their transcriptional activation domains (TADs). Here we show that the organization of the Ets-1/Pit-1 composite element tolerates significant flexibility with regard to Ras stimulation and synergy. Specifically, the putative monomeric Pit-1 binding site can be substituted with bona fide binding sites for either a Pit-1 monomer or dimer, and these sites tolerated a separation of 28 bp. Additionally, we show that the physical interaction of Ets-1 and Pit-1 is not required for Ras responsiveness or synergy because block mutations of the Pit-1 interaction surface in Ets-1, which reduced Ets-1/Pit-1 binding in vitro, did not significantly affect Ets-1 stimulation of Ras responsiveness or synergy. We also show differential use of distinct TAD subtypes and Pit-1 TAD subregions to mediate either synergy or Ras responsiveness. Specifically, TADs from Gal4, VP16, or Ets-2 regulatory III domain linked to Ets-1 DNA binding domain constructs restored synergy to these TAD/Ets-1 DNA binding domain fusions. Conversely, deletion of the defined Pit-1 TAD (amino acids 2-80) retained synergy, but not Ras responsiveness. Consequently, we further defined the Pit-1 amino-terminal TAD into region 1 (R1, amino acids 2-45) and region 2 (R2, amino acids 46 -80). R1 appears to regulate basal and synergistic responses, whereas the Ras response was mapped to R2. In summary, Ras responsiveness and Pit-1/Ets-1 synergy are mediated through the assembly of distinct TADs at a flexible composite element, indicating that different mechanisms underlie these two transcriptional responses and that the Pit-1 R2 subregion represents a novel, tissue-specific Ras-responsive TAD.

show abstract

Transcription factor Pit-1 expression is modulated upon seasonal acclimatization of eurythermal ectotherms: Identification of two Pit-1 genes in the carp

Kausel

Vera²,

Martin

et al. 1999

J. Cell. Biochem.

View full text Add to dashboard Cite

A second Pit-1 gene in carp (Cyprinus carpio), including the complete structural gene and 1.1 kb of promoter region, was identified and completely sequenced. The exon-intron structure was determined, and reverse transcription-polymerase chain reaction (RT-PCR) experiments suggest that only one Pit-1 splice variant is present in carp pituitary. The effect of seasonal acclimatization on the extent of Pit-1 gene expression was studied in summer- and winter-acclimatized carp. Quantitative RT-PCR analysis revealed a clear increase of Pit-1 mRNA in the pituitaries from summer-acclimatized carp compared with the winter-adapted fish. In situ hybridization of pituitary gland sections with riboprobes representing the complete 5'-transactivating region of carp Pit-1 depicted a significantly higher Pit-1 mRNA level in the rostral pars distalis of the summer-acclimatized fish where prolactin is expressed in a manner that resembles the seasonal increase observed in the proximal pars distalis and the pars intermedia. The cell- and temporal-specific transcription of Pit-1 supports its role in the molecular mechanisms that underly the acclimatization process undergone by eurythermal fish as a result of the physical effects of seasonal changes on their habitat.

show abstract

A 26-Amino Acid Insertion Domain Defines a Functional Transcription Switch Motif in Pit-1β

Cited by 24 publications

References 30 publications

Repression of the prolactin promoter: a functional consequence of the heterodimerization between Pit-1 and Pit-1 β

Repression of the prolactin promoter: a functional consequence of the heterodimerization between Pit-1 and Pit-1 β

Ras Signaling and Transcriptional Synergy at a Flexible Ets-1/Pit-1 Composite DNA Element Is Defined by the Assembly of Selective Activation Domains

Transcription factor Pit-1 expression is modulated upon seasonal acclimatization of eurythermal ectotherms: Identification of two Pit-1 genes in the carp

Contact Info

Product

Resources

About