Journal article
The major Leishmania donovani chagasi surface glycoprotein in tunicamycin-resistant promastigotes
The Journal of immunology (1950), Vol.144(12), pp.4825-4834
06/15/1990
DOI: 10.4049/jimmunol.144.12.4825
PMID: 2191040
Abstract
Two populations of Leishmania donovani chagasi promastigotes resistant to the lethal effects of tunicamycin (TM), an inhibitor of N-linked glycosylation, were raised. These parasites exhibited altered patterns of glycosylation when compared to wild-type controls. In particular the major surface glycoprotein gp63 was present in membranes of one population of TM-resistant promastigotes (population 1) primarily in a deglycosylated form, which migrated at a lower Mr than wild-type gp63. The deglycosylated protein was proteolytically inactive on substrate-containing gels, in contrast to glycosylated gp63. Assays of promastigote attachment to human macrophages revealed that, despite a proposed role for gp63 protease activity in binding to macrophage receptors, population 1 TM-resistant promastigotes appeared to attach to the CR3 but not to the mannose-fucose receptor. Control promastigotes bound to both receptors. In contrast, a second population of TM-resistant promastigotes (population 2) did not produce gp63 that could be detected on immunoblots, either in a glycosylated or deglycosylated form. The latter TM-resistant promastigotes bound to neither CR3 nor the mannose-fucose receptor, suggesting that expression of gp63 might be important for promastigotes to bind to CR3. LPG was present in immunoblots of both TM-resistant and control populations suggesting this molecule might not account for the differences in attachment. Surprisingly both TM-resistant promastigote populations contained gp63 mRNA by Northern analysis in apparently equal amounts. We conclude that N-glycosylation is probably necessary for the protease function of gp63, but that neither N-glycosylation nor protease activity of gp63 is necessary for L. donovani chagasi promastigotes to bind to CR3. Furthermore the expression of gp63 protein by TM-resistant promastigotes is dependent upon postranscriptional events.
Details
- Title: Subtitle
- The major Leishmania donovani chagasi surface glycoprotein in tunicamycin-resistant promastigotes
- Creators
- Mary E Wilson - Department of Internal Medicine, VA Medical Center, Iowa City, IAKristine K Hardin
- Resource Type
- Journal article
- Publication Details
- The Journal of immunology (1950), Vol.144(12), pp.4825-4834
- Publisher
- United States
- DOI
- 10.4049/jimmunol.144.12.4825
- PMID
- 2191040
- ISSN
- 0022-1767
- eISSN
- 1550-6606
- Grant note
- K11 AI00832 / NIAID NIH HHS
- Language
- English
- Date published
- 06/15/1990
- Academic Unit
- Microbiology and Immunology; International Programs; Epidemiology; Internal Medicine
- Record Identifier
- 9984002378602771
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