Acetylation-dependent chromatin reorganization by BRDT, a testis-specific bromodomain-containing protein.
The association between histone acetylation and replacement observed during spermatogenesis prompted us to consider the testis as a source for potential factors capable of remodelling acetylated chromatin. A systematic search of data banks for open reading frames encoding testis-specific bromodomain-containing proteins focused our attention on BRDT, a testis-specific protein of unknown function containing two bromodomains. BRDT specifically binds hyperacetylated histone H4 tail depending on the integrity of both bromodomains. Moreover, in somatic cells, the ectopic expression of BRDT triggered a dramatic reorganization of the chromatin only after induction of histone hyperacetylation by trichostatin A (TSA). We then defined critical domains of BRDT involved in its activity. Both bromodomains of BRDT, as well as flanking regions, were found indispensable for its histone acetylation-dependent remodelling activity. Interestingly, we also observed that recombinant BRDT was capable of inducing reorganization of the chromatin of isolated nuclei in vitro only when the nuclei were from TSA-treated cells. This assay also allowed us to show that the action of BRDT was ATP independent, suggesting a structural role for the protein in the remodelling of acetylated chromatin. This is the first demonstration of a large-scale reorganization of acetylated chromatin induced by a specific factor.
Pivot-Pajot
Christophe
C
Laboratoire de Biologie Moléculaire et Cellulaire de la Différenciation, INSERM U309, Equipe Chromatine et Expression des Gènes, Institut Albert Bonniot, Faculté de Médecine, Domaine de la Merci, 38706 La Tronche Cedex, France.
Caron
Cécile
C
Govin
Jérôme
J
Vion
Alexandre
A
Rousseaux
Sophie
S
Khochbin
Saadi
S
D016475:3T3 Cells; D000107:Acetylation; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D020224:Expressed Sequence Tags; D005822:Genetic Vectors; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics; D016366:Open Reading Frames; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013091:Spermatogenesis; D013347:Subcellular Fractions / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection; D000092468:Bromodomain Containing Proteins
D000255:Adenosine Triphosphate; D002843:Chromatin; D018076:DNA, Complementary; D006657:Histones; D006877:Hydroxamic Acids; D009687:Nuclear Proteins; D010455:Peptides; C109570:BRDT protein, human; D000092468:Bromodomain Containing Proteins; C012589:trichostatin A