Ligand-controlled interaction of histone acetyltransferase binding to ORC-1 (HBO1) with the N-terminal transactivating domain of progesterone receptor induces steroid receptor coactivator 1-dependent coactivation of transcription.
Modulators of cofactor recruitment by nuclear receptors are expected to play an important role in the coordination of hormone-induced transactivation processes. To identify such factors interacting with the N-terminal domain (NTD) of the progesterone receptor (PR), we used this domain as bait in the yeast Sos-Ras two-hybrid system. cDNAs encoding the C-terminal MYST (MOZ-Ybf2/Sas3-Sas2-Tip60 acetyltransferases) domain of HBO1 [histone acetyltransferase binding to the origin recognition complex (ORC) 1 subunit], a member of the MYST acetylase family, were thus selected from a human testis cDNA library. In transiently transfected CV1 cells, the wild-type HBO1 [611 amino acids (aa)] enhanced transcription mediated by steroid receptors, notably PR, mineralocorticoid receptor, and glucocorticoid receptor, and strongly induced PR and estrogen receptor coactivation by steroid receptor coactivator 1a (SRC-1a). As assessed by two-hybrid and glutathione-S-transferase pull-down assays, the HBO1 MYST acetylase domain (aa 340-611) interacts mainly with the NTD, and also contacts the DNA-binding domain and the hinge domains of hormone-bound PR. The HBO1 N-terminal region (aa 1-340) associates additionally with PR ligand-binding domain (LBD). HBO1 was found also to interact through its NTD with SRC-1a in the absence of steroid receptor. The latter coassociation enhanced specifically activation function 2 activation function encompassed in the LBD. Conversely, the MYST acetylase domain specifically enhanced SRC-1 coupling with PR NTD, through a hormone-dependent mechanism. In human embryonic kidney 293 cells expressing human PRA or PRB, HBO1 raised selectively an SRC-1-dependent response of PRB but failed to regulate PRA activity. We show that HBO1 acts through modification of an LBD-controlled structure present in the N terminus of PRB leading to the modulation of SRC-1 functional coupling with activation function 3-mediated transcription. Importantly, real-time RT-PCR analysis also revealed that HBO1 enhanced SRC-1 coactivation of PR-dependent transcription of human endogenous genes such as alpha-6 integrin and 11beta-hydroxydehydrogenase 2 but not that of amphiregulin. Immunofluorescence and confocal microscopy of human embryonic kidney-PRB cells demonstrated that the hormone induces the colocalization of HBO1 with PR-SRC-1 complex into nuclear speckles characteristic of PR-mediated chromatin remodeling. Our results suggest that HBO1 might play an important physiological role in human PR signaling.
Georgiakaki
Maria
M
Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 693, Faculté de Médecine Paris-Sud, 63 rue Gabriel Péri, 94276 Le Kremlin-Bicêtre Cedex, France.
Chabbert-Buffet
Nathalie
N
Dasen
Boris
B
Meduri
Geri
G
Wenk
Sandra
S
Rajhi
Leila
L
Amazit
Larbi
L
Chauchereau
Anne
A
Burger
Curt W
CW
Blok
Leen J
LJ
Milgrom
Edwin
E
Lombès
Marc
M
Guiochon-Mantel
Anne
A
Loosfelt
Hugues
H
D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D051548:Histone Acetyltransferases / Q000378:metabolism*; D006728:Hormones / Q000378:metabolism; D006801:Humans; D008024:Ligands; D056920:Nuclear Receptor Coactivator 1; D051738:Origin Recognition Complex / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics*
D006728:Hormones; D008024:Ligands; D051738:Origin Recognition Complex; D021122:Protein Subunits; D011980:Receptors, Progesterone; D011987:Receptors, Steroid; D014157:Transcription Factors; D051548:Histone Acetyltransferases; C496553:KAT7 protein, human; C538859:NCOA1 protein, human; D056920:Nuclear Receptor Coactivator 1