Epigenetic silencing of Plasmodium falciparum genes linked to erythrocyte invasion
| Autor: | Celine Carret, Alfred Cortés, Anthony A. Holder, Alasdair Ivens, Osamu Kaneko, Brian Y. S. Yim Lim |
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| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
lcsh:Immunologic diseases. Allergy
Plasmodium Erythrocytes 030231 tropical medicine Immunology Molecular Sequence Data Plasmodium falciparum Protozoan Proteins Biology Biochemistry Microbiology Epigenesis Genetic Host-Parasite Interactions 03 medical and health sciences 0302 clinical medicine Virology Gene expression Genetics Gene silencing Gene family Animals Humans Epigenetics Amino Acid Sequence Gene Silencing Gene Molecular Biology lcsh:QH301-705.5 030304 developmental biology Oligonucleotide Array Sequence Analysis 0303 health sciences Parasitic life cycles Membrane Proteins Genetics and Genomics Cell Biology biology.organism_classification 3. Good health Clone Cells Infectious Diseases Membrane protein lcsh:Biology (General) Parasitology Carrier Proteins lcsh:RC581-607 Research Article |
| Zdroj: | PLoS Pathogens, Vol 3, Iss 8, p e107 (2007) PLoS Pathogens |
| ISSN: | 1553-7374 1553-7366 |
| Popis: | The process of erythrocyte invasion by merozoites of Plasmodium falciparum involves multiple steps, including the formation of a moving junction between parasite and host cell, and it is characterised by the redundancy of many of the receptor–ligand interactions involved. Several parasite proteins that interact with erythrocyte receptors or participate in other steps of invasion are encoded by small subtelomerically located gene families of four to seven members. We report here that members of the eba, rhoph1/clag, acbp, and pfRh multigene families exist in either an active or a silenced state. In the case of two members of the rhoph1/clag family, clag3.1 and clag3.2, expression was mutually exclusive. Silencing was clonally transmitted and occurred in the absence of detectable DNA alterations, suggesting that it is epigenetic. This was demonstrated for eba-140. Our data demonstrate that variant or mutually exclusive expression and epigenetic silencing in Plasmodium are not unique to genes such as var, which encode proteins that are exported to the surface of the erythrocyte, but also occur for genes involved in host cell invasion. Clonal variant expression of invasion-related ligands increases the flexibility of the parasite to adapt to its human host. Author Summary Plasmodium falciparum is responsible for the most severe forms of human malaria. Invasion of host erythrocytes is an essential step of the complex life cycle of this parasite. There is redundancy in many of the interactions involved in this process, such that the parasite can use different sets of receptor–ligand interactions to invade. Here, we demonstrate that the parasite can turn off the expression of some of the proteins that mediate invasion of erythrocytes. Expression can be turned off without alterations in the genetic information of the parasite by using a mechanism known as epigenetic silencing. This is far more flexible than genetic changes, and permits fast, reversible adaptation. Turning on or off the expression of these proteins did not affect the capacity of the parasite to invade normal or modified red cells, which suggests that the variant expression of these genes may be used by the parasite to escape immune responses from the host. Parasite proteins that participate in erythrocyte invasion are important vaccine candidates. Determining which proteins can be turned off is important because vaccines based on single antigens of the parasite that can be turned off without affecting its growth would have little chance of inducing protective immunity. |
| Databáze: | OpenAIRE |
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