Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-23447
Stefanic, S; Morf, L; Kulangara, C; Regös, A; Sonda, S; Schraner, E M; Spycher, C; Wild, P; Hehl, A B (2009). Neogenesis and maturation of transient Golgi-like cisternae in a simple eukaryote. Journal of Cell Science, 122(Pt 16):2846-2856.
The highly reduced protozoan parasite Giardia lamblia has minimal machinery for cellular processes such as protein trafficking. Giardia trophozoites maintain diverse and regulated secretory pathways but lack an identifiable Golgi complex. During differentiation to cysts, however, they produce specialized compartments termed encystation-specific vesicles (ESVs). ESVs are hypothesized to be unique developmentally regulated Golgi-like organelles dedicated to maturation and export of pre-sorted cyst wall proteins. Here we present a functional analysis of this unusual compartment by direct interference with the functions of the small GTPases Sar1, Rab1 and Arf1. Conditional expression of dominant-negative variants revealed an essential role of Sar1 in early events of organelle neogenesis, whilst inhibition of Arf1 uncoupled morphological changes and cell cycle progression from extracellular matrix export. The latter led to development of ;naked cysts', which lacked water resistance and thus infectivity. Time-lapse microscopy and photobleaching experiments showed that putative Golgi-like cisternae in Giardia develop into a network capable of exchanging soluble cargo at a high rate via dynamic, tubular connections, presumably to synchronize maturation. The minimized and naturally pulsed trafficking machinery for export of the cyst wall biopolymer in Giardia is a simple model for investigating basic principles of neogenesis and maturation of Golgi compartments.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||05 Vetsuisse Faculty > Institute of Veterinary Anatomy|
05 Vetsuisse Faculty > Institute of Parasitology
04 Faculty of Medicine > Institute of Parasitology
|DDC:||570 Life sciences; biology|
610 Medicine & health
|Date:||15 August 2009|
|Deposited On:||28 Oct 2009 13:14|
|Last Modified:||23 Nov 2012 17:33|
|Publisher:||Company of Biologists|
|WoS Citation Count:||15|
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