A var gene promoter controls allelic exclusion of virulence genes in Plasmodium falciparum malaria

Voss, T.S., Healer, J., Marty, A.J., Duffy, M.F., Thompson, J.K., Beeson, J.G., Reeder, J.C., Crabb, B.S. and Cowman, A.F. (2006) A var gene promoter controls allelic exclusion of virulence genes in Plasmodium falciparum malaria. Nature, 439(7079), pp. 1004-1008. (doi: 10.1038/nature04407)

Full text not currently available from Enlighten.

Abstract

Mono-allelic expression of gene families is used by many organisms to mediate phenotypic variation of surface proteins. In the apicomplexan parasite Plasmodium falciparum, responsible for the severe form of malaria in humans, this is exemplified by antigenic variation of the highly polymorphic P. falciparum erythrocyte membrane protein 1 (PfEMP1)1, 2. PfEMP1, encoded by the 60-member vargene family3, 4, 5, 6, represents a major virulence factor due to its central role in immune evasion and intravascular parasite sequestration. Mutually exclusive expression of PfEMP1 is controlled by epigenetic mechanisms involving chromatin modification and perinuclear var locus repositioning7, 8. Here we show that a var promoter mediates the nucleation and spreading of stably inherited silenced chromatin. Transcriptional activation of this promoter occurs at the nuclear periphery in association with chromosome-end clusters. Additionally, the var promoter sequence is sufficient to infiltrate a transgene into the allelic exclusion programme of var gene expression, as transcriptional activation of this transgene results in silencing of endogenous var gene transcription. These results show that a var promoter is sufficient for epigenetic silencing and mono-allelic transcription of this virulence gene family, and are fundamental for our understanding of antigenic variation in P. falciparum. Furthermore, the PfEMP1 knockdown parasites obtained in this study will be important tools to increase our understanding of P. falciparum-mediated virulence and immune evasion.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Jackson, Dr Allison
Authors: Voss, T.S., Healer, J., Marty, A.J., Duffy, M.F., Thompson, J.K., Beeson, J.G., Reeder, J.C., Crabb, B.S., and Cowman, A.F.
College/School:College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Nature
ISSN:0028-0836
ISSN (Online):1476-4687

University Staff: Request a correction | Enlighten Editors: Update this record