| Autor: |
Sharp, Sarah, Lavstsen, Thomas, Fivelman, Quinton L., Saeed, Maha, McRobert, Louisa, Templeton, Thomas J., Jensen, Anja T. R., Baker, David A., Theander, Thor G., Sutherland, Colin J. |
| Zdroj: |
Eukaryotic Cell; August 2006, Vol. 5 Issue: 8 p1206-1214, 9p |
| Abstrakt: |
ABSTRACTThe vargenes encode Plasmodium falciparumerythrocyte membrane protein 1 (PfEMP1) proteins, a set of highly diverse surface-expressed proteins that mediate adhesion of erythrocytes infected with asexual blood-stage parasites to host endothelium. Switching among expressed PfEMP1 variants in the course of a blood-stage infection is a key component of antigenic variation, and thus immune evasion, by the parasite. The majority of varloci are found in the subtelomeric regions of P. falciparumchromosomes associated with members of other multigene families, including stevor. Both PfEMP1 and STEVOR are expressed in gametocytes, the transmissible parasite stage, but the role of these proteins in the biology of sexual-stage parasites remains unknown. PfEMP1 may continue to mediate antigenic variation in gametocytes, which need to persist in the host for many days before reaching maturity. Using quantitative reverse transcription-PCR and Northern hybridization, we demonstrate that transcription of a defined subset of type C varloci occurs during gametocyte development in vitro. This transcriptional program occurs in gametocytes regardless of the varexpression phenotype of their asexual progenitors and therefore is subject to regulatory processes distinct from those that manage antigenic variation in the asexual parasite. In contrast, the same stevorvariants are transcribed in both gametocytes and their asexual progenitors. We also provide evidence that for both asexual parasites and gametocytes, varand stevortranscription patterns are not linked to each other. |
| Databáze: |
Supplemental Index |
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