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Sara Della Torre, Gianpaolo Rando, Clara Meda, Paolo Ciana, Luisa Ottobrini and Adriana Maggi

active in most reproductive and non-reproductive tissue cells ( Ciocca & Roig 1995 , Maggi et al. 2004 , Bookout et al. 2006 ). Their expression and transcriptional activity in the course of embryo development is less studied ( Brandenberger et al

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CG Korkmaz, K Fronsdal, Y Zhang, PI Lorenzo and F Saatcioglu

Androgens are critical in the development and maintenance of the male reproductive system and important in the progression of prostate cancer. The effects of androgens are mediated by the androgen receptor (AR), which is a ligand-modulated transcription factor that belongs to the nuclear receptor superfamily. We and others have previously shown that CREB-binding protein (CBP) can function as a coactivator for AR. Similar to some other nuclear receptor coactivators and/or the proteins that they interact with, CBP has histone acetyl transferase (HAT) activity that is thought to contribute to transcriptional activation by nuclear receptors. We have therefore assessed whether an increase in the histone acetylation status in the cell can influence AR transcriptional activity, by using the histone deacetylase (HDAC) inhibitors (HDACIs) trichostatin A (TSA), sodium butyrate (Na-But) and depsipeptide (FR901228). We found that inhibition of HDAC activity significantly increased the ability of endogenous AR in LNCaP cells, or ectopically expressed AR in HeLa cells, to activate transcription from AR-dependent reporter constructs. In addition, HDACIs increased the androgen-dependent activation of the prostate-specific antigen (PSA) gene in LNCaP cells, an increase that was not due to an increase in nuclear AR protein levels. Moreover, the viral oncoprotein E1A that inhibits CBP HAT activity fully repressed the ability of HDACIs to stimulate AR-mediated transcription, indicating that CBP is involved in this process. Deletional mutagenesis of AR indicated that whereas the AF-2 domain in the C-terminus is dispensable, the AF-1 domain in the N-terminus is required for augmentation of AR action by HDACIs, an observation which is in concordance with the reduced ability of CBP to activate AR N-terminal deletion mutants. Furthermore, HDACI treatment rescued the deficiency in the transactivation potential of AF-2 mutants. Taken together, our findings suggest that a change in the level of histone acetylation of target genes is an important determinant of AR action, possibly mediated by CBP.

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Miroslav Adzic, Jelena Djordjevic, Ana Djordjevic, Ana Niciforovic, Constantinos Demonacos, Marija Radojcic and Marija Krstic-Demonacos

-releasing hormone (CRH), brain-derived neurotropic factor (BDNF), and cytokines ( Goujon et al . 1997 , Schulkin et al . 1998 , Morsink et al . 2006 , Schulte-Herbruggen et al . 2006 ). The GR transcriptional activity is dependent on the cell type, the

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L Dalla Valle, V Toffolo, A Nardi, C Fiore, P Bernante, R Di Liddo, PP Parnigotto and L Colombo

reverse transcriptase (RT)-PCR its steroidogenic competence, the expression of organic anion transporters belonging to the OATP and OAT families, the transmembrane transport of DHEA-S, the transcriptional control of the gene encoding STS, and the specific

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JA Stirland, ZC Seymour, S Windeatt, AJ Norris, P Stanley, MG Castro, AS Loudon, MR White and Davis JR

Although analysis of luciferase activity using luminescence imaging has provided new insights into the dynamic regulation of gene expression in living tIssues, studies in vitro have relied on stably transfected clonal cell lines, limiting the choice of cell type and species, or DNA microinjection, which is arduous and highly selective. We report here the first use of a recombinant adenovirus in which the firefly luciferase reporter gene was regulated by the prolactin gene promoter, to study temporal dynamics of promoter activity. This vector was used to infect the pituitary GH3 cell line, and also primary cultures of Syrian hamster pituitary cells. We show that adenovirally transduced cells retained normal regulation of the promoter-reporter transgene by appropriate signals. Furthermore, microscopic imaging studies indicated that both clonal and primary pituitary cells were transduced efficiently, giving readily detectable luminescence signals in real-time over long periods. Finally, analysis of single-cell expression patterns indicated that prolactin promoter activity was highly dynamic with pulses in gene expression, revealing that the transcriptional instability seen in clonal cells is a feature of normal pituitary cells. Adenoviral vectors offer a valuable tool for studies of gene regulation where conventional transgenesis and clonal cell lines are not available.

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Colin W Hay, Elaine M Sinclair, Giovanna Bermano, Elaine Durward, Mohammad Tadayyon and Kevin Docherty

transcription to 0.70, 0.58 and 0.66 relative to the unmutated construct respectively (Fig. 4B ). These data show that all four CRE sites in the human insulin promoter are transcriptionally active and that there could be constitutive cAMP/PKA activity in INS-1

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Jee H Lee, Jamie L Volinic, Constanze Banz, Kwok-Ming Yao and Melissa K Thomas

complexes through interactions with a large repertoire of transcription factors and components of basal transcription machinery ( Chan & La Thangue 2001 , Vo & Goodman 2001 ). The intrinsic acetyltransferase activity of p300 augments the activation of gene

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Melyssa R Bratton, James W Antoon, Bich N Duong, Daniel E Frigo, Syreeta Tilghman, Bridgette M Collins-Burow, Steven Elliott, Yan Tang, Lilia I Melnik, Ling Lai, Jawed Alam, Barbara S Beckman, Steven M Hill, Brian G Rowan, John A McLachlan and Matthew E Burow

. Dopamine has been shown to activate ER-mediated transcriptional activity in the absence ( Power et al . 1991 ) or presence ( Smith et al . 1993 ) of E 2 . Melatonin has been shown to inhibit breast cancer cell proliferation through modulation of ERα

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Masaya Takeda, Fumio Otsuka, Hiroyuki Otani, Kenichi Inagaki, Tomoko Miyoshi, Jiro Suzuki, Yukari Mimura, Toshio Ogura and Hirofumi Makino

reported by Pernasetti et al. (2001) . It was of note that PPAR agonists suppressed transcriptional activities of FSHβ , LHβ , and GnRHR in Lβ T2 cells (Fig. 5 ). To assess the mechanism by which PPAR agonists affect activin signaling in Lβ T2

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Marta Labeur, Damian Refojo, Barbara Wölfel, Johanna Stalla, Vivian Vargas, Marily Theodoropoulou, Michael Buchfelder, Marcelo Paez-Pereda, Eduardo Arzt and Günter K Stalla

dominant role in mediating stimulation by CRH ( Murphy & Conneely 1997 , Philips et al . 1997 a , Maira et al . 1999 ). CRH also induces transcriptional activity of activating protein 1 (AP1) and cAMP-responsive element-binding protein 1 (CREB1), which