Characterisation and expression of a stage-regulated gene of Leishmania major

Nourbakhsh, Fahimeh; Uliana, Sílvia Reni Bortolin; Smith, Deborah F.

doi:10.1016/0166-6851(95)02559-6

Cited by 42 publications

(33 citation statements)

References 25 publications

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“…WT parasites produced 7.8% and 10.4% metacyclic forms in two cultures, whereas ⌬lmgt parasites produced 2.5% metacyclic forms in both cases. Furthermore the meta 1 transcript, which is up-regulated in metacyclic parasites (33), was induced 3.6-fold in WT stationary-phase compared with mid-logarithmic phase parasites, whereas the transcript was induced 1.7-fold in stationary-phase ⌬lmgt cells. By these criteria, metacyclogenesis appears to be impaired but not abrogated in glucose transporter null mutants.…”

Section: Development Of Metacyclic Promastigotes In Wt and ⌬Lmgt Paramentioning

confidence: 97%

Genetic characterization of glucose transporter function inLeishmania mexicana

Burchmore

Rodriguez‐Contreras

McBride

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

127

165

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Both insect and mammalian life cycle stages of Leishmania mexicana take up glucose and express all three isoforms encoded by the LmGT glucose transporter gene family. To evaluate glucose transporter function in intact parasites, a null mutant line has been created by targeted disruption of the LmGT locus that encompasses the LmGT1, LmGT2, and LmGT3 genes. This Δlmgt null mutant exhibited no detectable glucose transport activity. The growth rate of the Δlmgt knockout in the promastigote stage was reduced to a rate comparable with that of WT cells grown in the absence of glucose. Δlmgt cells also exhibited dramatically reduced infectivity to macrophages, demonstrating that expression of LmGT isoforms is essential for viability of amastigotes. Furthermore, WT L. mexicana were not able to grow as axenic culture form amastigotes if glucose was withdrawn from the medium, implying that glucose is an essential nutrient in this life cycle stage. Expression of either LmGT2 or LmGT3, but not of LmGT1, in Δlmgt null mutants significantly restored growth as promastigotes, but only LmGT3 expression substantially rescued amastigote growth in macrophages. Subcellular localization of the three isoforms was investigated in Δlmgt cells expressing individual LmGT isoforms. Using anti-LmGT antiserum and GFP-tagged LmGT fusion proteins, LmGT2 and LmGT3 were localized to the cell body, whereas LmGT1 was localized specifically to the flagellum. These results establish that each glucose transporter isoform has distinct biological functions in the parasite

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Section: Development Of Metacyclic Promastigotes In Wt and ⌬Lmgt Paramentioning

confidence: 97%

Genetic characterization of glucose transporter function inLeishmania mexicana

Burchmore

Rodriguez‐Contreras

McBride

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

127

165

View full text Add to dashboard Cite

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“…Finally, stationaryphase drug-resistant parasites express less Meta-1 than drug-sensitive cells [43]. This marker is the product of the meta-1 gene, originally described in L. major [61]; it is highly conserved both in Old and New World parasites and is predominantly expressed in metacyclic promastigotes of Leishmania [61,62]. As previously mentioned, the only reliable current method for monitoring resistance of isolates is the technically demanding in vitro amastigote/macrophage model [14].…”

Section: Metacyclogenesis In Drug-resistant Leishmaniamentioning

confidence: 95%

Leishmania spp.: proficiency of drug-resistant parasites

Natera

Machuca

Padrón-Nieves

et al. 2007

International Journal of Antimicrobial Agents

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“…This suggests that the − 36 AG may act as an alternative trans-splicing site, even though the − 42 AG is used under wild-type conditions, probably because it is the first AG after the polypyrimidine tracts. This preference for the AG immediately downstream of the polypyrimidine tracts has been reported for L. major and L. donovani (Hendrickson et al, 1993;Roberts et al, 1993;Charest et al, 1996), although there are some exceptions when the initial AG is located closely to the polypyrimidine tract (Langford et al, 1992;Hendrickson et al, 1993;Nourbakhsh et al, 1996). In the MAT2 gene, there is an eight-pyrimidine motif 11-bp upstream of the − 42 wild-type AG (GenBank accession no.…”

Section: Discussionmentioning

confidence: 84%