Trypanosomes change their transferrin receptor expression to allow effective uptake of host transferrin

Summary In its mammalian host, Trypanosoma brucei covers its iron requirements by receptor‐mediated uptake of host transferrin (Tf). The Tf‐receptor (Tf‐R) is a heterodimeric membrane protein encoded by expression site‐associated gene (ESAG) 6 and 7 located promoter‐proximal in a polycistronic expre...

Full description

Saved in:
Bibliographic Details
Published in:Molecular microbiology 2005-10, Vol.58 (1), p.151-165
Main Authors: Van Luenen, Henri G. A. M., Kieft, Rudo, Mußmann, Rainer, Engstler, Markus, Ter Riet, Bas, Borst, Piet
Format: Article
Language:English
Subjects:
Animals
Biological and medical sciences
Blotting, Western
Body fluids
Cattle
Culture Media
Dogs
Fundamental and applied biological sciences. Psychology
Gene Deletion
Gene expression
Gene Expression Regulation
Glycoproteins - analysis
Glycoproteins - genetics
Microbiology
Proteins
Protozoan Proteins - analysis
Protozoan Proteins - genetics
Receptors, Transferrin - genetics
Receptors, Transferrin - metabolism
Recombination, Genetic
RNA, Messenger - analysis
RNA, Protozoan - analysis
T cell receptors
Transferrin - metabolism
Trypanosoma brucei brucei - genetics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Summary In its mammalian host, Trypanosoma brucei covers its iron requirements by receptor‐mediated uptake of host transferrin (Tf). The Tf‐receptor (Tf‐R) is a heterodimeric membrane protein encoded by expression site‐associated gene (ESAG) 6 and 7 located promoter‐proximal in a polycistronic expression site (ES). Each of the 20 ESs encodes a slightly different Tf‐R; these differences strongly affect the binding affinity for Tfs of different hosts. The Tf‐R encoded in the 221 ES has a low affinity for dog Tf. Transfer of trypanosomes with an active 221 ES to dilute dog serum leads to growth arrest, which they can overcome by switching to another ES encoding a Tf‐R with higher affinity for dog Tf. Here we show that trypanosomes can also adapt to dilute dog serum without switching but by replacing the ESAG7 gene in the 221 ES by one from another ES, by deleting ESAG7 from the 221 ES with concomitant upregulation of transcription of ESAG7 in ‘silent’ ESs, by grossly overproducing the 221 Tf‐R or by combinations of these alterations. Our results illustrate the striking genetic flexibility of trypanosomes.
ISSN:0950-382X
1365-2958
DOI:10.1111/j.1365-2958.2005.04831.x