TY - JOUR
T1 - Transcriptional repression by AML1 and LEF-1 is mediated by the TLE/Groucho corepressors
AU - Levanon, Ditsa
AU - Goldstein, Robert E.
AU - Bernstein, Yael
AU - Tang, Hua
AU - Goldenberg, Dalia
AU - Stifan, Stefano
AU - Paroush, Ze'ev
AU - Groner, Yoram
PY - 1998/9/29
Y1 - 1998/9/29
N2 - The mammalian AML/CBFα runt domain (RD) transcription factors regulate hematopoiesis and osteoblast differentiation. Like their Drosophila counterparts, most mammalian RD proteins terminate in a common pentapeptide, VWRPY, which serves to recruit the corepressor Groucho (Gro). Using a yeast two-hybrid assay, in vitro association and pull-down experiments, we demonstrate that Gro and its mammalian homolog TLE1 specifically interact with AML1 and AML2. In addition to the VWRPY motif, other C-terminal sequences are required for these interactions with Gro/TLE1. TLE1 inhibits AML1-dependent transactivation of the T cell receptor (TCR) enhancers α and β, which contain functional AML binding sites, in transfected Jurkat T cells. LEF-1 is an additional transcription factor that mediates transactivation of TCR enhancers. LEF-1 and its Drosophila homolog Pangolin (Pan) are involved in the Wnt/Wg signaling pathway through interactions with the coactivator β-catenin and its highly conserved fly homolog Armadillo (Arm). We show that TLE/Gro interacts with LEF-1 and Pan, and inhibits LEF- 1:β-catenin-dependent transcription. These data indicate that, in addition to their activity as transcriptional activators, AML1 and LEF-1 can act, through recruitment of the corepressor TLE1, as transcriptional repressors in TCR regulation and Wnt/Wg signaling.
AB - The mammalian AML/CBFα runt domain (RD) transcription factors regulate hematopoiesis and osteoblast differentiation. Like their Drosophila counterparts, most mammalian RD proteins terminate in a common pentapeptide, VWRPY, which serves to recruit the corepressor Groucho (Gro). Using a yeast two-hybrid assay, in vitro association and pull-down experiments, we demonstrate that Gro and its mammalian homolog TLE1 specifically interact with AML1 and AML2. In addition to the VWRPY motif, other C-terminal sequences are required for these interactions with Gro/TLE1. TLE1 inhibits AML1-dependent transactivation of the T cell receptor (TCR) enhancers α and β, which contain functional AML binding sites, in transfected Jurkat T cells. LEF-1 is an additional transcription factor that mediates transactivation of TCR enhancers. LEF-1 and its Drosophila homolog Pangolin (Pan) are involved in the Wnt/Wg signaling pathway through interactions with the coactivator β-catenin and its highly conserved fly homolog Armadillo (Arm). We show that TLE/Gro interacts with LEF-1 and Pan, and inhibits LEF- 1:β-catenin-dependent transcription. These data indicate that, in addition to their activity as transcriptional activators, AML1 and LEF-1 can act, through recruitment of the corepressor TLE1, as transcriptional repressors in TCR regulation and Wnt/Wg signaling.
UR - http://www.scopus.com/inward/record.url?scp=0032578394&partnerID=8YFLogxK
U2 - 10.1073/pnas.95.20.11590
DO - 10.1073/pnas.95.20.11590
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C2 - 9751710
AN - SCOPUS:0032578394
SN - 0027-8424
VL - 95
SP - 11590
EP - 11595
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 20
ER -