FB1, an E2A fusion partner in childhood leukemia, interacts with U19/EAF2 and inhibits its transcriptional activity.
BACKGROUND
U19/EAF2 is a potential tumor suppressor exhibiting frequent down-regulation and allelic loss in advanced human prostate cancer specimens. U19/EAF2 has also been identified as ELL-associated factor 2 (EAF2) based on its binding to ELL, a fusion partner of MLL in acute myeloid leukemia. U19/EAF2 is a putative transcription factor with a transactivation domain and capability of sequence-specific DNA binding.


METHODS
Yeast-two-hybrid-screening was used to identify U19/EAF2-binding partners. Co-immunoprecipitation and mammalian 1-hybrid assay were used to characterize a U19/EAF2-binding partner.


RESULTS
FB1, an E2A fusion partner in childhood leukemia, was identified as a binding-partner of U19/EAF2. FB1 also binds to EAF1, the only homologue of U19/EAF2. FB1 also interacts and co-localizes with ELL in the nucleus. Interestingly, FB1 inhibited the transcriptional activity of U19/EAF2 but not EAF1.


CONCLUSIONS
FB1 is an important binding partner and a functional regulator of U19/EAF2, EAF1, and/or ELL.
Jiang
Feng
F
Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
Ai
Junkui
J
Xiao
Wuhan
W
Wang
Zhou
Z
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000032:analysis / Q000378:metabolism*; D019556:COS Cells; D002522:Chlorocebus aethiops; D006801:Humans; D047468:Immunoprecipitation; D014157:Transcription Factors / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000032:analysis / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D051792:Basic Helix-Loop-Helix Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C431383:EAF1 protein, human; C472771:EAF2 protein, human; C090862:ELL protein, human; C118089:TFPT protein, human