Nuclear repositioning of the VSG promoter during developmental silencing in Trypanosoma brucei

65Citations
Citations of this article
70Readers
Mendeley users who have this article in their library.
Get full text

Abstract

Interphase nuclear repositioning of chromosomes has been implicated in the epigenetic regulation of RNA polymerase (pol) II transcription. However, little is known about the nuclear position-dependent regulation of RNA pol I-transcribed loci. Trypanosoma brucei is an excellent model system to address this question because its two main surface protein genes, procyclin and variant surface glycoprotein ( VSG), are transcribed by pol I and undergo distinct transcriptional activation or downregulation events during developmental differentiation. Although the monoallelically expressed VSG locus is exclusively localized to an extranucleolar body in the bloodstream form, in this study, we report that nonmutually exclusive procyclin genes are located at the nucleolar periphery. Interestingly, ribosomal DNA loci and pol I transcription activity are restricted to similar perinucleolar positions. Upon developmental transcriptional downregulation, however, the active VSG promoter selectively undergoes a rapid and dramatic repositioning to the nuclear envelope. Subsequently, the VSG promoter region was subjected to chromatin condensation. We propose a model whereby the VSG expression site pol I promoter is selectively targeted by temporal nuclear repositioning during develop mental silencing. © The Rockefeller University Press.

Cite

CITATION STYLE

APA

Landeira, D., & Navarro, M. (2007). Nuclear repositioning of the VSG promoter during developmental silencing in Trypanosoma brucei. Journal of Cell Biology, 176(2), 133–139. https://doi.org/10.1083/jcb.200607174

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free