The recurrent chromosome 16 inversion in acute myeloid leukemia generates a fusion gene between CBFB and MYH11, which in turn encodes a chimeric protein CBF-SMMHC (core binding factor -smooth muscle myosin heavy chain).   We previously demonstrated that CBF-SMMHC needs its C terminal domains for leukemogenesis.  In this study, we generated a new Cbfb-MYH11 knock-in mouse model to dissect the role of the multimerization domain at the C terminus of CBF-SMMHC.  Specifically, we mutated six amino acids in the helices D and E (mDE) of the assembly competent domain, which is important for SMMHC multimerization.  We found that the embryos with the mDE mutation (Cbfb+/mDE) did not develop hematopoietic defects seen in embryos with full-length CBF-SMMHC (Cbfb+/MYH11).  More importantly leukemia development was abolished in the adult Cbfb+/mDE mice even after mutagenesis treatment.  In addition, gene expression profile of the hematopoietic cells from the Cbfb+/mDE mice was more similar to that of Cbfb+/+ mice than the Cbfb+/MYH11 mice. Our data suggest that the C terminal multimerization domain is required for the defects in primitive and definitive hematopoiesis caused by CBF-SMMHC, and it is also essential for leukemogenesis caused by CBF-SMMHC. SOURCE: Pu,Paul,Liu (pliu@nih.gov) - ODS NHGRI/NIH

Pluto Bioinformatics

GSE100061: The C-terminal multimerization domain is essential for leukemia development by CBF-SMMHC