title: Distribution of the chromatin protein DEK distinguishes active and inactive CD21/CR2 gene in pre- and mature B lymphocytes.
abstract: DEK is an abundant and ubiquitous chromatin protein that has only recently attracted attention. DEK preferentially binds to cruciform and superhelical DNA and induces positive supercoils into closed circular DNA. It is quite likely therefore that DEK performs an important architectural function in chromatin. However, it is not known how DEK is distributed in chromatin. As the first study of its kind, we investigate the distribution of DEK at the CD21/complement receptor 2 gene regulatory regions in two B lymphocyte lines, namely Ramos, which expresses the CD21 gene, and Nalm-6, which does not. We use a chromatin immunoprecipitation approach and show that DEK appears to be distributed over various regions of the expressed and silent genes, but occurs in 2- to 3-fold higher amounts at a promoter-proximal site of the expressed gene. Moreover, induction of CD21 expression in Nalm-6 cells leads to accumulation of DEK at this site. We propose that the accumulation of DEK is functionally linked to gene expression.
authors.affiliation: Department of Biology, University of Konstanz, D-78457 Konstanz, Germany. hong-gang.hu@uni-konstanz.de
authors.forename: Hong-gang
authors.initials: HG
authors.lastname: Hu
authors.forename: Harald
authors.initials: H
authors.lastname: Illges
authors.forename: Claudia
authors.initials: C
authors.lastname: Gruss
authors.forename: Rolf
authors.initials: R
authors.lastname: Knippers
mesh_terms: D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000276:immunology; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis / Q000378:metabolism*; D000077209:Decitabine; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D015513:Oncogene Proteins / Q000032:analysis / Q000378:metabolism*; D000075223:Poly-ADP-Ribose Binding Proteins; D011401:Promoter Regions, Genetic; D017464:Receptors, Complement 3d / Q000032:analysis / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C084738:DEK protein, human; D015513:Oncogene Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D017464:Receptors, Complement 3d; D000077209:Decitabine; D001374:Azacitidine