Regulation of matrix attachment region-dependent, lymphocyte-restricted transcription through differential localization within promyelocytic leukemia nuclear bodies.

ABSTRACT: Bright (B cell regulator of IgH transcription) transactivates the immunoglobulin heavy chain (IgH) intronic enhancer, Emicro, by binding to matrix attachment regions (MARs), sites necessary for DNA attachment to the nuclear matrix. Here we report that Bright interacts with the ubiquitous autoantigen Sp100, a component of promyelocytic leukemia nuclear bodies (PML NBs), and with LYSp100B/Sp140, the lymphoid-restricted homolog of Sp100. Both in intact cells and in nuclear matrix preparations, the majority of Bright and Sp100 colocalize within PML NBs. In contrast, Bright colocalizes with only a small fraction of LYSp100B while inducing a redistribution of the majority of LYSp100B from its associated nuclear domains (LANDs) into nucleoplasm and cytoplasm. Sp100 represses the MAR-binding and t

SUBMITTER: Zong RT 

PROVIDER: S-EPMC306587 | biostudies-literature | 2000 Aug

REPOSITORIES: biostudies-literature