E2A-PBX1 interacts directly with the KIX domain of CBP/p300 in the induction of proliferation in primary hematopoietic cells.
The E2A gene encodes DNA-binding transcription factors, called E12 and E47, involved in cell specification and maturation. E2A is also involved in a chromosomal translocation that leads to the expression of an oncogenic transcription factor called E2A-PBX1 in cases of acute leukemia. In the work described here, we elucidate the interaction between E2A-PBX1 and transcriptional co-activators. We confirm that the E2A portion can interact with CBP and PCAF and map required elements on E2A and CBP. On CBP, the interaction involves the KIX domain, a well characterized domain that mediates interactions with several other oncogenic transcription factors. On E2A, the interaction with CBP requires conserved alpha-helical domains that reside within activation domains 1 and 2 (AD1 and AD2, respectively). Using purified, recombinant proteins, we show that the E2A-CBP interaction is direct. Notwithstanding the previously demonstrated ability of AD1 and AD2 to function independently, some of our findings suggest functional cooperativity between these two domains. Finally, we show that the CBP/p300-interactive helical domains of E2A are important in the induction of proliferation in cultured primary bone marrow cells retrovirally transduced with E2A-PBX1. Our findings suggest that some aspects of E2A-PBX1 oncogenesis involve a direct interaction with the KIX domain of CBP/p300.
Bayly
Richard
R
Queen's University Cancer Research Institute, Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
Chuen
Luan
L
Currie
Richard A
RA
Hyndman
Brandy D
BD
Casselman
Richard
R
Blobel
Gerd A
GA
LeBrun
David P
DP
D000595:Amino Acid Sequence; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism; D002453:Cell Cycle; D049109:Cell Proliferation; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D050881:E1A-Associated p300 Protein; D005347:Fibroblasts / Q000378:metabolism; D017353:Gene Deletion; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology*; D015514:Oncogene Proteins, Fusion / Q000737:chemistry / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D012190:Retroviridae / Q000235:genetics; D016196:S Phase; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014178:Translocation, Genetic; D020798:Two-Hybrid System Techniques
D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D015514:Oncogene Proteins, Fusion; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D015534:Trans-Activators; C089847:E2A-Pbx1 fusion protein; D004247:DNA; D008156:Luciferases; D050881:E1A-Associated p300 Protein; C494361:Ep300 protein, mouse; D005982:Glutathione Transferase