The transferrin receptor in African trypanosomes: identification, partial characterization and subcellular localization
- PMID: 8269969
The transferrin receptor in African trypanosomes: identification, partial characterization and subcellular localization
Abstract
All eukaryotic cells, including African trypanosomes, require iron for growth and division, and this iron is acquired by the receptor-mediated endocytosis of iron-loaded transferrin (diFe(3+)-transferrin). In trypanosomes transferrin (Tf) has been shown to be delivered into lysosomes and may not recycle back to the cell surface as it does in mammalian cells (Grab, D. J., et al., Eur. J. Cell Biol. 59, 398-404 (1992)). Here, we describe for the first time, the characteristics of a Tf-binding protein with receptor-like properties in Trypanosoma brucei brucei. Bloodstream forms of rodent-adapted T. brucei were incubated with [35S]methionine and detergent lysates chromatographed on a Sephacryl S-300 column. Fractions were incubated with anti-Tf serum to immunoprecipitate Tf/Tf-binding protein complexes. On sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) the molecular mass of the major protein in the immunoprecipitate was 88 to 92 kDa. Tf-binding proteins could also be isolated using diferric Tf-Sepharose. The molecular mass of the major Tf-binding protein, as estimated from Sephacryl S-300 column chromatography, in the presence of detergent, was approximately 90 to 100 kDa and 90 kDa with SDS-PAGE. Each 90 kDa Tf-binding protein was able to bind one molecule of diferric Tf. Since monoclonal antibodies to human and bovine Tf receptors failed to react with any trypanosome proteins, antisera were raised against the T. brucei Tf-binding proteins eluted from Tf-Sepharose at low pH. These antibodies recognized a 90 kDa protein on Western blots of a T. brucei lysate and inhibited the growth of T. brucei in vitro. Immunolocalization studies, using this antiserum showed that the Tf-binding protein was localized in the flagellar pocket and within the early endosomal compartments. In the presence of protease inhibitors there was additional localization in lysosome-like organelles. The Tf-binding characteristics and localization of this 90 kDa protein suggest that this molecule is a strong candidate as a physiological receptor for Tf in these parasites.
Similar articles
-
Endocytosed transferrin in African trypanosomes is delivered to lysosomes and may not be recycled.Eur J Cell Biol. 1992 Dec;59(2):398-404. Eur J Cell Biol. 1992. PMID: 1493805
-
Trypanosoma brucei transferrin receptor can bind C-lobe and N-lobe fragments of transferrin.Mol Biochem Parasitol. 2012 Oct;185(2):99-105. doi: 10.1016/j.molbiopara.2012.06.007. Epub 2012 Jul 7. Mol Biochem Parasitol. 2012. PMID: 22776208
-
Trypanosoma brucei rhodesiense: membrane glycoproteins localized primarily in endosomes and lysosomes of bloodstream forms.Exp Parasitol. 1993 Jun;76(4):329-44. doi: 10.1006/expr.1993.1041. Exp Parasitol. 1993. PMID: 7685707
-
Surface receptors and transporters of Trypanosoma brucei.Annu Rev Microbiol. 1998;52:745-78. doi: 10.1146/annurev.micro.52.1.745. Annu Rev Microbiol. 1998. PMID: 9891812 Review.
-
The transferrin receptor of Trypanosoma brucei.Parasitol Int. 2000 Jan;48(3):191-8. doi: 10.1016/s1383-5769(99)00018-5. Parasitol Int. 2000. PMID: 11227758 Review.
Cited by
-
The Trypanosoma brucei MISP family of invariant proteins is co-expressed with BARP as triple helical bundle structures on the surface of salivary gland forms, but is dispensable for parasite development within the tsetse vector.PLoS Pathog. 2023 Mar 30;19(3):e1011269. doi: 10.1371/journal.ppat.1011269. eCollection 2023 Mar. PLoS Pathog. 2023. PMID: 36996244 Free PMC article.
-
Pseudokinase NRP1 facilitates endocytosis of transferrin in the African trypanosome.Sci Rep. 2022 Nov 3;12(1):18572. doi: 10.1038/s41598-022-22054-x. Sci Rep. 2022. PMID: 36329148 Free PMC article.
-
Overview of the role of kinetoplastid surface carbohydrates in infection and host cell invasion: prospects for therapeutic intervention.Parasitology. 2019 Dec;146(14):1743-1754. doi: 10.1017/S0031182019001355. Epub 2019 Oct 11. Parasitology. 2019. PMID: 31603063 Free PMC article. Review.
-
The Flagellum Attachment Zone: 'The Cellular Ruler' of Trypanosome Morphology.Trends Parasitol. 2016 Apr;32(4):309-324. doi: 10.1016/j.pt.2015.12.010. Epub 2016 Jan 8. Trends Parasitol. 2016. PMID: 26776656 Free PMC article. Review.
-
How Does the VSG Coat of Bloodstream Form African Trypanosomes Interact with External Proteins?PLoS Pathog. 2015 Dec 31;11(12):e1005259. doi: 10.1371/journal.ppat.1005259. eCollection 2015 Dec. PLoS Pathog. 2015. PMID: 26719972 Free PMC article. Review.
MeSH terms
Substances
LinkOut - more resources
Research Materials
Miscellaneous