Evidence for binding of extrachromosomal DNA sequences to nuclear matrix proteins in multidrug‐resistant KB‐V1 cells

FEBS Letters

Hanauske, Axel-R.²  Thiebaut, Franz¹  Von Hoff, Daniel D.³ 

[1] University of California San Diego Cancer Center, 220 W. Dickinson St., San Diego, CA 92103, USA;Abteilung Hämatologie und Onkologie. I. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, Ismaningerstr. 22, D-8000 München 80, Germany;Department of Medicine, Division of Oncology, Section of Drug Development, University of Texas Health Science Center at San Antonio. 7703 Floyd Curl Dr., San Antonio, TX 78284, USA

关键词: Episome;    Plasmid;    Nuclear matrix;    Drug resistance;    KB-V1 cell;   

DOI  :  10.1016/0014-5793(93)80052-V

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Multidrug-resistant KB-V1 cells carry amplified mdrl gene sequences located in an extrachromosomal compartment (on episomes). Since episomes do not contain centromeric or telomeric sequences it is unclear whether they are able to bind to nuclear matrix proteins that may regulate episomal gene expression. Using high salt treatments followed by in situ hybridization and dot blot analyses we found evidence for direct binding of episomal DNA to nuclear matrix proteins. This binding could only be reversed after incubation with trypsin or proteinase K as determined by contour-clamped homogeneous electric field (CHEF) electrophoresis. Our findings are consistent with the concept that circular extrachromosomal DNA may not only reintegrate into nuclear DNA but may also be subject to functional control by regulatory proteins within the nuclear matrix.

【 授权许可】

Unknown