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Titolo:
The major cell surface glycoprotein procyclin is a receptor for induction of a novel form of cell death in African trypanosomes in vitro
Autore:
Pearson, TW; Beecroft, RP; Welburn, SC; Ruepp, S; Roditi, I; Hwa, KY; Englund, PT; Wells, CW; Murphy, NB;
Indirizzi:
Univ Victoria, Dept Biochem & Microbiol, Victoria, BC V8W 3P6, Canada UnivVictoria Victoria BC Canada V8W 3P6 ol, Victoria, BC V8W 3P6, Canada Univ Edinburgh, Royal Dick Sch Vet Med, Ctr Trop Vet Med, Vector Res Grp, Roslin EH25 9RG, Midlothian, Scotland Univ Edinburgh Roslin Midlothian Scotland EH25 9RG , Midlothian, Scotland Univ Bern, Inst Allgemeine Mikrobiol, CH-3012 Bern, Switzerland Univ BernBern Switzerland CH-3012 Mikrobiol, CH-3012 Bern, Switzerland Johns Hopkins Univ, Sch Med, Dept Biol Chem, Baltimore, MD 21205 USA JohnsHopkins Univ Baltimore MD USA 21205 l Chem, Baltimore, MD 21205 USA Int Livestock Res Inst, Nairobi, Kenya Int Livestock Res Inst Nairobi Kenya Livestock Res Inst, Nairobi, Kenya
Titolo Testata:
MOLECULAR AND BIOCHEMICAL PARASITOLOGY
fascicolo: 2, volume: 111, anno: 2000,
pagine: 333 - 349
SICI:
0166-6851(200012)111:2<333:TMCSGP>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
ACIDIC REPETITIVE PROTEIN; BRUCEI-RHODESIENSE; CULTURE FORMS; TSETSE-FLY; STRUCTURAL CHARACTERIZATION; MONOCLONAL-ANTIBODIES; BLOOD-STREAM; STAGE; IDENTIFICATION; CONGOLENSE;
Keywords:
cell death; African trypanosomes; procyclics; procyclin; lectin; receptor; glycoprotein; concanavalin A;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
50
Recensione:
Indirizzi per estratti:
Indirizzo: Pearson, TW Univ Victoria, Dept Biochem & Microbiol, Petch Bldg,POB 3055, Victoria, BCV8W 3P6, Canada Univ Victoria Petch Bldg,POB 3055 Victoria BC Canada V8W 3P6 a
Citazione:
T.W. Pearson et al., "The major cell surface glycoprotein procyclin is a receptor for induction of a novel form of cell death in African trypanosomes in vitro", MOL BIOCH P, 111(2), 2000, pp. 333-349

Abstract

Bloodstream forms (BSF) and procyclic culture forms (PCF) of African trypanosomes were incubated with a variety of lectins in vitro. Cessation of cell division and profound morphological changes were seen in procyclic forms but not in BSF after incubation with concanavalin A (Con A): wheat germ agglutinin and Ricinus communis agglutinin. These lectins caused the trypanosomes to cease division, become round and increase dramatically in size, the latter being partially attributable to the formation of what appeared to bea large 'vacuole-like structure' or an expanded flagellar pocket. Con A was used in all further experiments. Spectrophotometric quantitation of extracted DNA and flow cytometry using the DNA intercalating dye propidium iodide showed that the DNA content of Con A-treated trypanosomes increased dramatically when compared to untreated parasites. Examination of these cells byfluorescence microscopy showed that many of the Con A-treated cells were multinucleate whereas the kinetoplasts were mostly present as single copies,indicating a disequilibrium between nuclear and kinetoplast replication. Immunofluorescence experiments using monoclonal antibodies (mAb) specific for paraflagellar rod proteins and for kinetoplastid membrane protein-11 (KMP-11), showed that the Con A-treated parasites had begun to duplicate the flagellum but that this had only proceeded along part of the length of the cells, suggesting that the cell division process was initiated but that cytokinesis was subsequently inhibited. Tunicamycin-treated wild-type trypanosomes and mutant trypanosomes expressing both high levels of non-glycosylated procyclins and procyclin isoforms with truncated N-linked sugars were resistant to the effects of Con A, suggesting that N-linked carbohydrates on theprocyclin surface coat were the ligands for Con A binding. This was supported by data obtained using mutant parasites created by deletion of all three EP procyclin isoforms, two of which contain N-glycosylation sites, by homologous recombination. The knockout mutants showed reduced binding of fluorescein-labelled Con A as determined by flow cytometry and were resistant tothe effects of Con A. Taken together the results show that Con A induces multinucleation, a disequilibrium between nuclear and kinetoplast replication. and a unique form of cell death in procyclic African trypanosomes and that the ligands for Con A binding are carbohydrates on the EP forms of procyclin. The possible significance of these findings for the life cycle of thetrypanosomes in the tsetse fly vector is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/11/20 alle ore 10:28:59