BioProject

Switch/sucrose nonfermentable (SWI/SNF) complexes are ATP-dependent chromatin remodeler complexes that play critical roles in timely and appropriate gene regulation by modulating chromatin architecture and DNA accessibility. More...

Switch/sucrose nonfermentable (SWI/SNF) complexes are ATP-dependent chromatin remodeler complexes that play critical roles in timely and appropriate gene regulation by modulating chromatin architecture and DNA accessibility. SWI/SNF complexes can be grouped into three subcomplexes of differing sizes, canonical BAF (cBAF), polybromo BAF (PBAF), and newly identified noncanonical BAF (ncBAF). The most recently characterized ncBAF lacks the core BAF subunits ARID, BAF47, and BAF57, but includes unique subunits GLTSCR1/1L and BRD9, one of the bromodomain-containing proteins.We recently demonstrated the novel mechanism for the ncBAF disruption caused by mutations in a spiceosomal protein, SF3B1, especially in 65–83% for myelodysplastic syndromes (MDS) with ring sideroblasts as well as in >20% of mucosal/uveal melanomas, suggesting that the disturbed ncBAF may have some roles in the malignant hematopoiesis.Mechanistically, SF3B1 mutant recognizes an aberrant, deep intronic branchpoint within BRD9 and thereby induces the inclusion of an aberrant exon and subsequently profound degradation of BRD9 mRNA by triggering nonsense-mediated RNA decay (NMD). However, compared to the roles of cBAF, the functions of BRD9/ncBAF in normal and malignant hematopoiesis in vivo have been totally uncharacterized. Overall design: 2.0 x 10E6 total BM cells of Mx1-Cre control, Mx1-Cre Brd9fl/fl mice transplanted via tail vein injection into lethally irradiated (two times 450 cGy) CD45.1+ recipient mice. Four weeks after BMT, the recipient mice received 20 mg/kg pIpC injection every other day for a total of 3 doses. Five months after pIpC injection, the recipient mice were sacrificed for sample preparation. Less...