Traffic. 2013 Aug 20. doi: 10.1111/tra.12102. [Epub ahead of print]

Toxoplasma gondii Syntaxin 6 is required for vesicular transport between endosomal-like compartments and the Golgi

Jackson AJ, Clucas C, Mamczur NJ, Ferguson DJ, Meissner M.

Source

Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, The University of Glasgow, Glasgow, G12 8TA, United Kingdom.

Abstract

Apicomplexans are obligate intracellular parasites that invade the host cell in an active process that relies on unique secretory organelles (micronemes, rhoptries, and dense granules) localised at the apical tip of these highly polarised eukaryotes. In order for the contents of these specialised organelles to reach their final destination, these proteins are sorted post-Golgi and it has been speculated that they pass through endosomal-like compartments, where they undergo maturation. Here we characterise a Toxoplasma gondii homolog of Syntaxin 6 (TgStx6), a well-established marker for the early endosomes and trans-Golgi network (TGN) in diverse eukaryotes. Indeed TgStx6 appears to have a role in the retrograde transport between endosomal-like compartments, the TGN and the Golgi, since overexpression of TgStx6 results in the development of abnormally shaped parasites with expanded endosomal-like compartments, a fragmented Golgi and a defect in inner membrane complex maturation. Interestingly, other organelles, such as the micronemes, rhoptries and the apicoplast are not affected, establishing the TGN as a major sorting compartment where several transport pathways intersect. It therefore appears that Toxoplasma has retained a plant-like secretory pathway.

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KEYWORDS:

Golgi, Syntaxin, TGN, Toxoplasma gondii, conditional mutant, endosomes, vesicular traffic

PMID: 

23962112 

[PubMed - as supplied by publisher]