Skip to main content
. 2021 Aug 25;10:e65872. doi: 10.7554/eLife.65872

Figure 4. MLL-ELL transforms through the common binding platform for AF4 and EAF1.

(A) Requirement of the occludin homology domain (OHD) in MLL-ELL-mediated transformation. Various MLL-ELL constructs carrying mutations in the ELL portion were examined for the transformation of myeloid progenitors, as in Figure 1A. NHD: N-terminal homology domain; ALF: AF4/LAF4/FMR2 homology domain; pSER: poly-serine; A9ID: AF9 interaction domain; CHD: C-terminal homology domain; EHD: EAF family homology domain; DLXLS: DLXLS motif; SDE: SDE motif. (B) OHD-dependent association with AF4. Immunoprecipitation (IP)-western blotting of the chromatin fraction of virus-packaging cells, transiently expressing various HA-tagged MTMT-ELL fusion constructs, was performed. Endogenous AF4 proteins co-purified with MTMTh-ELL proteins were visualized by an anti-AF4 antibody. (C) Sequential recruitment of AF4 and EAF1 by ELL. HEK293TL cells (Okuda et al., 2015), which harbor GAL4-responsive reporter, were transfected with various combinations of FLAG-tagged GAL4 fusion proteins, xAF4, and HA-tagged EAF1 (EAF1h), and were subjected to chromatin immunoprecipitation (ChIP)-qPCR analysis. A qPCR probe near the GAL4-responsive elements (UAS) was used. The ChIP signals were expressed as the percent input with error bars (mean ± SD of PCR triplicates). TATA: TATA box; LUC: luciferase. (D) Effects of overexpression of AF4 or EAF1 on ELL complex formation. IP-western blotting of the chromatin fraction of HEK293TL cells, transiently expressing various combinations of FLAG-tagged GAL4-ELL proteins, xAF4, and EAF1h, was performed. (E) A model of the sequential association between ELL, AF4 family proteins, and EAF family proteins.

Figure 4.

Figure 4—figure supplement 1. Functions of the ELL portion.

Figure 4—figure supplement 1.

(A) Virus-packaging cells transiently expressing each MLL fusion construct were analyzed by western blotting with indicated antibodies. (B) Recruitment of exogenously expressed AF4 or EAF1 by ELL. HEK293TL cells (Okuda et al., 2015), which harbor GAL4-responsive reporter, were transfected with FLAG-tagged GAL4 fusion proteins, xAF4, and HA-tagged EAF1 (EAF1h), and were subjected to chromatin immunoprecipitation (ChIP)-qPCR analysis. A qPCR probe near the GAL4-responsive elements (UAS) was used. The ChIP signals were expressed as the percent input with error bars (mean ± SD of PCR triplicates). TATA: TATA box; LUC: luciferase. (C) Association of ELL with exogenously expressed AF4 or EAF1 on chromatin. Immunoprecipitation (IP)-western blotting of the chromatin fraction of HEK293TL cells transiently expressing various FLAG-tagged GAL4-ELL proteins along with xAF4 and EAF1h was performed.