Dominant IgM synthesis against the soluble form of the prevailing variant surface glycoprotein from TeAp-N/D1 Trypanosoma equiperdum throughout the experimental acute infections of horses with non-tsetse transmitted Trypanozoon parasites

2020 ◽  
Vol 41 (4) ◽  
pp. 745-760
Author(s):  
Graciela L. Uzcanga ◽  
José Bubis
Keyword(s):  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Soluble Form ◽  
Acute Infections ◽  
Trypanosoma Equiperdum

DNA rearrangements and antigenic variation in Trypanosoma equiperdum: expression-independent DNA rearrangements in the basic copy of a variant surface glycoprotein gene

1983 ◽  
Vol 3 (3) ◽  
pp. 410-414
Author(s):  
S Longacre ◽  
A Raibaud ◽  
U Hibner ◽  
G Buck ◽  
H Eisen ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Antigenic Variation ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Dna Rearrangements ◽  
Present Evidence ◽  
Glycoprotein Gene ◽  
Copy Gene ◽  
Genomic Environment ◽  
Trypanosoma Equiperdum

Antigenic variation in Trypanosoma equiperdum is associated with the sequential expression of variant surface glycoprotein (VSG) genes in a process which involves gene duplication and transposition events. In this paper we present evidence that the genomic environment of the VSG-1 basic copy gene, the template for duplicated, expression-linked VSG-1 genes, differs in every trypanosome clone examined. This variation is thus independent of the expression of the VSG-1 gene, and it also appears to be restricted to the 3' genomic environment. It is also demonstrated that the DNA located 3' to the VSG-1 basic copy gene is moderately sensitive to digestion when the nuclei of either expressor or non-expressor trypanosomes are treated with DNase I.

Identification of potential protein partners that bind to the variant surface glycoprotein in Trypanosoma equiperdum

Parasitology ◽  
2017 ◽  
Vol 144 (7) ◽  
pp. 923-936 ◽  
Author(s):  
LIOMARY M. CARRASQUEL ◽  
JOSÉ L. ESCALONA ◽  
ALVARO ACOSTA-SERRANO ◽  
YURONG GUO ◽  
JOSÉ BUBIS
Keyword(s):  
Antigenic Variation ◽  
Orthologous Gene ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Western Blots ◽  
Binding Partners ◽  
Protein Partners ◽  
Expression Site ◽  
Tryparedoxin Peroxidase ◽  
Trypanosoma Equiperdum

SUMMARYTrypanosoma equiperdum possesses a dense coat of a variant surface glycoprotein (VSG) that is used to evade the host immune response by a process known as antigenic variation. Soluble and membrane forms of the predominant VSG from the Venezuelan T. equiperdum TeAp-N/D1 strain (sVSG and mVSG, respectively) were purified to homogeneity; and antibodies against sVSG and mVSG were raised, isolated, and employed to produce anti-idiotypic antibodies that structurally mimic the VSG surface. Prospective VSG-binding partners were initially detected by far-Western blots, and then by immunoblots using the generated anti-idiotypic antibodies. Polypeptides of ~80 and 55 kDa were isolated when anti-idiotypic antibodies–Sepharose affinity matrixes were used as baits. Mass spectrometry sequencing yielded hits with various proteins from Trypanosoma brucei such as heat-shock protein 70, tryparedoxin peroxidase, VSG variants, expression site associated gene product 6, and two hypothetical proteins. In addition, a possible interaction with a protein homologous to the glutamic acid/alanine-rich protein from Trypanosoma congolense was also found. These results indicate that the corresponding orthologous gene products are candidates for VSG-interacting proteins in T. equiperdum.

scholarly journals Identification of glycosylphosphatidylinositol-specific phospholipases C in mouse brain membranes

1990 ◽  
Vol 269 (2) ◽  
pp. 321-327 ◽  
Author(s):  
F Fouchier ◽  
T Baltz ◽  
G Rougon
Keyword(s):  
Plasma Membrane ◽  
Phospholipase C ◽  
Mouse Brain ◽  
The Other ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Acidic Ph ◽  
Lysosomal Compartment ◽  
Membrane Compartment ◽  
Trypanosoma Equiperdum

Using the membrane form of variant surface glycoprotein from Trypanosoma equiperdum labelled with [3H]myristate as a substrate, we identified two glycosylphosphatidylinositol phospholipase C enzymic activities in mouse brain. These activities were associated with particulate membrane fractions. They were characterized by their pH activity maxima and sensitivity to activators and ion chelators. One of the activities was maximal at acidic pH, stimulated by butanol, sensitive to cation chelator and insensitive to manganese. The activity of the other was maximal at neutral pH, stimulated by the detergent deoxycholate and independent of the presence of cation chelator or calcium. On membrane subfractionation, the acidic butanol-stimulated activity was found mainly associated with the lysosomal compartment, whereas the neutral deoxycholate-stimulated activity sediments with the myelin and plasma membrane compartment. These activities could be differentiated from particulate phosphatidylinositol phospholipases C, whose acidic lysosomal form is sensitive to manganese and insensitive to cation chelator or butanol, whereas the deoxycholate-activated enzymes are Ca2(+)-dependent.

scholarly journals Cloning and characterization of a variant surface glycoprotein expression site from Trypanosoma equiperdum.

1986 ◽  
Vol 6 (8) ◽  
pp. 2950-2956 ◽  
Author(s):  
A Raibaud ◽  
G Buck ◽  
T Baltz ◽  
H Eisen
Keyword(s):  
Trypanosoma Brucei ◽  
Southern Blot Analysis ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
African Trypanosomes ◽  
Active Expression ◽  
Expression Site ◽  
Trypanosoma Equiperdum ◽  
Dna Fragment

Variant surface glycoprotein (VSG) genes of African trypanosomes are expressed when they are inserted into one of several telomere-linked expression sites. We cloned and characterized an 11-kilobase (kb) DNA fragment located upstream of an expressed VSG gene. A DNA sequence of 1.8 kb that is located immediately upstream of the inserted VSG gene contains sequences homologous to the 76-base-pair repeats described as being upstream of VSG genes in Trypanosoma brucei (D. A. Campbell, M. P. Van Bree, and J. C. Boothroyd, Nucleic Acids Res. 12:2759-2774). There are no such sequences elsewhere in the 11-kb cloned region. Southern blot analysis using probes from the cloned region revealed multiple unlinked copies of the same or very similar regions. At least three of these are located near telomeres, and two have been shown to be used for the expression of known Trypanosoma equiperdum VSG genes. Like VSG genes, the upstream sequences themselves can be duplicated and deleted. The choice of expression site to be used by a duplicated VSG gene is nonrandom; the site used for expression of the parental VSG gene is strongly favored for use in the daughter variant. Furthermore, even when the parental expression site is not used, the VSG gene occupying it is replaced. Thus, an active expression site is a preferential target for gene conversion in the next variation event.

scholarly journals Exposed epitopes on a Trypanosoma equiperdum variant surface glycoprotein altered by point mutations.

1991 ◽  
Vol 10 (7) ◽  
pp. 1653-1659 ◽  
Author(s):  
T. Baltz ◽  
C. Giroud ◽  
F. Bringaud ◽  
H. Eisen ◽  
C. Jacquemot ◽  
...  
Keyword(s):  
Point Mutations ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Trypanosoma Equiperdum
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