Amplification of an alternate transporter gene suppresses the avirulent phenotype of glucose transporter null mutants inLeishmania mexicana
| Autor: | Dayana Rodriguez-Contreras, Scott M. Landfear, Elizabeth Kruvand, Xiuhong Feng, H. G. Archie Bouwer, Cosmo Buffalo, Stephen M. Beverley |
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| Rok vydání: | 2009 |
| Předmět: |
Monosaccharide Transport Proteins
Genes Protozoan Leishmania mexicana Mutant Protozoan Proteins Microbiology Article Mice Gene expression Animals Molecular Biology Gene Hexoses Oligonucleotide Array Sequence Analysis Comparative Genomic Hybridization Mice Inbred BALB C Expression vector biology Permease Macrophages Genetic Complementation Test Gene Amplification Glucose transporter biology.organism_classification Molecular biology Complementation Phenotype Mutation RNA Protozoan |
| Zdroj: | Molecular Microbiology. 71:369-381 |
| ISSN: | 1365-2958 0950-382X |
| Popis: | A glucose transporter null mutant of the parasitic protozoan Leishmania mexicana, in which three linked glucose transporter genes have been deleted by targeted gene replacement, is unable to replicate as amastigote forms within phagolysomes of mammalian host macrophages and is avirulent. Spontaneous suppressors of the null mutant have been isolated that partially restore replication of parasites within macrophages. These suppressor mutants have amplified the gene for an alternative hexose transporter, the LmGT4 permease (previously called the D2 permease), on a circular extrachromosomal element, and they overexpress LmGT4 mRNA and protein. The suppressors have also regained the ability to transport hexoses, and they have reverted other phenotypes of the null mutant exhibiting enhanced resistance to oxidative killing, heat shock and starvation for nutrients, as well as augmented levels of the storage carbohydrate beta-mannan, increased cell size and increased growth as insect stage promastigotes compared with the unsuppressed mutant. Complementation of the null mutant with the LmGT4 gene on a multicopy episomal expression vector also reverted these phenotypes, confirming that suppression results from amplification of the LmGT4 gene. These results underscore the importance of hexose transporters for the infectious stage of the parasite life cycle. |
| Databáze: | OpenAIRE |
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