Rab5b localization to early endosomes in the protozoan human pathogen Leishmania donovani
Leishmania donovani is a primitive trypanosomatid pathogen of humans. This protozoan is apically polarized such that the flagellar reservoir, the exclusive site of endocytosis and exocytosis, is situated at the anterior end. Recent evidence for the existence of an endocytic pathway in Leishmania has prompted us to investigate candidate temporal markers for endocytosis. In this study we identify the L. donovani Rab5b gene, and demonstrate the localization of a Rab5b chimera to early endosomes. A full-length Rab5b protein was fused to green fluorescent protein (GFP) to generate a chimeric protein GFP::Rab5b. Transfected L. donovani promastigotes carrying this chimeric construct displayed GFP::Rab5b localization. Additionally, incubation of transfected promastigotes with the fluid-phase marker Texas Red dextran demonstrated anterior co-localization of GFP::Rab5b and dye. This suggests Rab5b may act as a marker for early endosomes in L. donovani.
Keywordsendocytosis GFP chimera Leishmania Rab5b trafficking
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- 7.Duclos S, Diez R, Garin J, Papadopoulou B, Descoteau A, Stenmark H, Desjardins M: Rab5 regulates the kiss and run fusion between phagosomes and endosomes and the acquisition of phagosome leishmanicidal properties in RAW 264.7 macrophages. J Cell Sci 113: 3531–3541, 2000Google Scholar
- 10.Bates PA, Hermes I, Dwyer DM: Golgi-mediated post-translational processing of secretory acid phosphatase by Leishmania donovani promastigotes. Mol Biochem Parasitol 392: 247–256, 1990Google Scholar
- 13.McCombie WR, Heiner C, Kelley JM, Fitzgerald MG, Gocayne JD: Rapid and reliable fluorescent cycle sequencing of double-stranded templates. DNA Seq. 2: 289–296, 1992Google Scholar
- 15.Swofford DL. PAUP∗. Phylogenetic Analysis Using Parsimony (∗and Other Methods). Version 4. Sunderland, Massachusetts: Sinauer Associates 2002.Google Scholar
- 16.Zhang WW, Charest H, Ghedin E, Matlashewshi G: Identification and overexpression of the A2 amastigote-specific protein in Leishmania donovani. Mol Biochem Parasitol 78: 79–90, 1996Google Scholar
- 22.Pereira-Leal JB, Strom M, Godfrey RF, Seabra, MC. Structural determinants of Rab and Rab escort protein interaction: Rab family motifs define a conserved binding surface. Biochem Biophys Res Commun 301: 92–97, 2003Google Scholar
- 23.Feng Y, Press B, Wardinger-Ness A: Rab7: an important regulator of the late endocytic membrane traffic. J Biol Chem 131: 1435–1452, 1995Google Scholar
- 25.Bucci C, Parton RG, Mather IH, Stunnenberg H, Simons K, Hoflack B, Zerial M. The small GTPase Rab5b functions as a regulatory factor in the early endocytic pathway. Cell 70: 715–728, 1992Google Scholar