Abstract
Concanavalin A (Con A) kills procyclic (insect) forms of Trypanosoma brucei by binding to N-glycans on EP-procyclin, a major surface glycosyl phosphatidylinositol (GPI)-anchored protein which is rich in Glu-Pro repeats. We have previously isolated and studied two procyclic mutants (ConA 1-1 and ConA 4-1) that are more resistant than wild-type (WT) to Con A killing. Although both mutants express the same altered oligosaccharides compared to WT cells, ConA 4-1 is considerably more resistant to lectin killing than is ConA 1-1. Thus, we looked for other alterations to account for the differences in sensitivity. Using mass spectrometry, together with chemical and enzymatic treatments, we found that both mutants express types of EP-procyclin that are either poorly expressed or not found at all in WT cells. ConA 1-1 expresses mainly EP1-3, a novel procyclin that contains 18 EP repeats, is partially N-glycosylated, and bears hybrid-type glycans. On the other hand, ConA 4-1 cells express almost exclusively EP2-3, a novel non-glycosylated procyclin isoform with 23 EP repeats and no site for glycosylation. The predominance of EP2-3 in ConA 4-1 cells explains their high resistance to ConA killing. Thus, switching the procyclin repertoire, a process that could be relevant to parasite development in the insect vector, modulates the sensitivity of trypanosomes to cytotoxic lectins. (C) 2000 Academic Press.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 633-644 |
| Number of pages | 12 |
| Journal | Journal of Molecular Biology |
| Volume | 304 |
| Issue number | 4 |
| DOIs | |
| State | Published - Dec 8 2000 |
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Keywords
- Glycosyl phosphatidylinositol
- Mass spectrometry
- N-glycosylation
- Procyclin
- Trypanosome
ASJC Scopus subject areas
- Virology
Cite this
Killing of Trypanosoma brucei by Concanavalin A : Structural basis of resistance in glycosylation mutants. / Acosta-Serrano, Alvaro; Cole, Robert N; Englund, Paul T.
In: Journal of Molecular Biology, Vol. 304, No. 4, 08.12.2000, p. 633-644.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Killing of Trypanosoma brucei by Concanavalin A
T2 - Structural basis of resistance in glycosylation mutants
AU - Acosta-Serrano, Alvaro
AU - Cole, Robert N
AU - Englund, Paul T.
PY - 2000/12/8
Y1 - 2000/12/8
N2 - Concanavalin A (Con A) kills procyclic (insect) forms of Trypanosoma brucei by binding to N-glycans on EP-procyclin, a major surface glycosyl phosphatidylinositol (GPI)-anchored protein which is rich in Glu-Pro repeats. We have previously isolated and studied two procyclic mutants (ConA 1-1 and ConA 4-1) that are more resistant than wild-type (WT) to Con A killing. Although both mutants express the same altered oligosaccharides compared to WT cells, ConA 4-1 is considerably more resistant to lectin killing than is ConA 1-1. Thus, we looked for other alterations to account for the differences in sensitivity. Using mass spectrometry, together with chemical and enzymatic treatments, we found that both mutants express types of EP-procyclin that are either poorly expressed or not found at all in WT cells. ConA 1-1 expresses mainly EP1-3, a novel procyclin that contains 18 EP repeats, is partially N-glycosylated, and bears hybrid-type glycans. On the other hand, ConA 4-1 cells express almost exclusively EP2-3, a novel non-glycosylated procyclin isoform with 23 EP repeats and no site for glycosylation. The predominance of EP2-3 in ConA 4-1 cells explains their high resistance to ConA killing. Thus, switching the procyclin repertoire, a process that could be relevant to parasite development in the insect vector, modulates the sensitivity of trypanosomes to cytotoxic lectins. (C) 2000 Academic Press.
AB - Concanavalin A (Con A) kills procyclic (insect) forms of Trypanosoma brucei by binding to N-glycans on EP-procyclin, a major surface glycosyl phosphatidylinositol (GPI)-anchored protein which is rich in Glu-Pro repeats. We have previously isolated and studied two procyclic mutants (ConA 1-1 and ConA 4-1) that are more resistant than wild-type (WT) to Con A killing. Although both mutants express the same altered oligosaccharides compared to WT cells, ConA 4-1 is considerably more resistant to lectin killing than is ConA 1-1. Thus, we looked for other alterations to account for the differences in sensitivity. Using mass spectrometry, together with chemical and enzymatic treatments, we found that both mutants express types of EP-procyclin that are either poorly expressed or not found at all in WT cells. ConA 1-1 expresses mainly EP1-3, a novel procyclin that contains 18 EP repeats, is partially N-glycosylated, and bears hybrid-type glycans. On the other hand, ConA 4-1 cells express almost exclusively EP2-3, a novel non-glycosylated procyclin isoform with 23 EP repeats and no site for glycosylation. The predominance of EP2-3 in ConA 4-1 cells explains their high resistance to ConA killing. Thus, switching the procyclin repertoire, a process that could be relevant to parasite development in the insect vector, modulates the sensitivity of trypanosomes to cytotoxic lectins. (C) 2000 Academic Press.
KW - Glycosyl phosphatidylinositol
KW - Mass spectrometry
KW - N-glycosylation
KW - Procyclin
KW - Trypanosome
UR - http://www.scopus.com/inward/record.url?scp=0034624085&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034624085&partnerID=8YFLogxK
U2 - 10.1006/jmbi.2000.4246
DO - 10.1006/jmbi.2000.4246
M3 - Article
VL - 304
SP - 633
EP - 644
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 4
ER -