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A Multigene Family Encoding R‐SNAREs in the Ciliate Paramecium tetraurelia
Author(s) -
Schilde Christina,
Wassmer Thomas,
Mansfeld Joerg,
Plattner Helmut,
KissmehI Roland
Publication year - 2006
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2006.00397.x
Subject(s) - biology , ciliate , paramecium , genetics , encoding (memory) , microbiology and biotechnology , neuroscience
SNARE proteins (soluble N ‐ethylmaleimide‐sensitive factor attachment protein receptors) mediate membrane interactions and are conventionally divided into Q‐SNAREs and R‐SNAREs according to the possession of a glutamine or arginine residue at the core of their SNARE domain. Here, we describe a set of R‐SNAREs from the ciliate Paramecium tetraurelia consisting of seven families encoded by 12 genes that are expressed simultaneously. The complexity of the endomembrane system in Paramecium can explain this high number of genes. All P. tetraurelia synaptobrevins ( Pt Sybs) possess a SNARE domain and show homology to the Longin family of R‐SNAREs such as Ykt6, Sec22 and tetanus toxin‐insensitive VAMP (TI‐VAMP). We localized four exemplary Pt Syb subfamilies with GFP constructs and antibodies on the light and electron microscopic level. Pt Syb1‐1, Pt Syb1‐2 and Pt Syb3‐1 were found in the endoplasmic reticulum, whereas Pt Syb2 is localized exclusively in the contractile vacuole complex. Pt Syb6 was found cytosolic but also resides in regularly arranged structures at the cell cortex (parasomal sacs), the cytoproct and oral apparatus, probably representing endocytotic compartments. With gene silencing, we showed that the R‐SNARE of the contractile vacuole complex, Pt Syb2, functions to maintain structural integrity as well as functionality of the osmoregulatory system but also affects cell division.