title: Association of the transcriptional corepressor TIF1beta with heterochromatin protein 1 (HP1): an essential role for progression through differentiation.
abstract: The transcriptional intermediary factor 1beta (TIF1beta) is a corepressor for KRAB-domain-containing zinc finger proteins and is believed to play essential roles in cell physiology by regulating chromatin organization at specific loci through association with chromatin remodeling and histone-modifying activities and recruitment of heterochromatin protein 1 (HP1) proteins. In this study, we have engineered a modified embryonal carcinoma F9 cell line (TIF1beta(HP1box/-)) expressing a mutated TIF1beta protein (TIF1beta(HP1box)) unable to interact with HP1 proteins. Phenotypic analysis of TIF1beta(HP1box/-) and TIF1beta(+/-) cells shows that TIF1beta-HP1 interaction is not required for differentiation of F9 cells into primitive endoderm-like (PrE) cells on retinoic acid (RA) treatment but is essential for further differentiation into parietal endoderm-like (PE) cells on addition of cAMP and for differentiation into visceral endoderm-like cells on treatment of vesicles with RA. Complementation experiments reveal that TIF1beta-HP1 interaction is essential only during a short window of time within early differentiating PrE cells to establish a selective transmittable competence to terminally differentiate on further cAMP inducing signal. Moreover, the expression of three endoderm-specific genes, GATA6, HNF4, and Dab2, is down-regulated in TIF1beta(HP1box/-) cells compared with wild-type cells during PrE differentiation. Collectively, these data demonstrate that the interaction between TIF1beta and HP1 proteins is essential for progression through differentiation by regulating the expression of endoderm differentiation master players.
authors.affiliation: Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP/Collège de France, BP10142, 67404 Illkirch, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Cammas
authors.forename: Marielle
authors.initials: M
authors.lastname: Herzog
authors.forename: Thierry
authors.initials: T
authors.lastname: Lerouge
authors.forename: Pierre
authors.initials: P
authors.lastname: Chambon
authors.forename: Régine
authors.initials: R
authors.lastname: Losson
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics*; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D000242:Cyclic AMP; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004707:Endoderm / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D050993:GATA6 Transcription Factor; D005786:Gene Expression Regulation; D016147:Genes, Tumor Suppressor; D005816:Genetic Complementation Test; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D051557:Hepatocyte Nuclear Factor 4; D006801:Humans; D018613:Microscopy, Confocal; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D010750:Phosphoproteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism; D014212:Tretinoin; D000076183:Tripartite Motif-Containing Protein 28; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D051017:Apoptosis Regulatory Proteins; D002868:Chromosomal Proteins, Non-Histone; C102885:DAB2 protein, human; D017931:DNA Primers; D004268:DNA-Binding Proteins; D050993:GATA6 Transcription Factor; C494759:GATA6 protein, human; D051557:Hepatocyte Nuclear Factor 4; D010750:Phosphoproteins; D012097:Repressor Proteins; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D000090266:Chromobox Protein Homolog 5; D014212:Tretinoin; D000242:Cyclic AMP; C101116:TRIM28 protein, human; D000076183:Tripartite Motif-Containing Protein 28