In:
Journal of Cell Science, The Company of Biologists, Vol. 118, No. 19 ( 2005-10-01), p. 4551-4562
Abstract:
Trypanosomes are protozoan parasites that have a major impact on human health and that of livestock. These parasites represent a very early branch in the eukaryotic linage, and possess unique RNA processing mechanisms. The trypanosome signal recognition particle (SRP) is also unusual in being the first signal recognition particle described in nature to be comprised of two RNA molecules, the 7SL RNA and a tRNA-like molecule. In this study, we further elucidated the unique properties of this particle. The genes encoding three SRP proteins (SRP19, SRP72 and SRP68) were identified by bioinformatics analysis. Silencing of these genes by RNAi suggests that the SRP-mediated protein translocation pathway is essential for growth. The depletion of SRP72 and SRP68 induced sudden death, most probably as a result of toxicity due to the accumulation of the pre-SRP in the nucleolus. Purification of the trypanosome particle to homogeneity, by TAP-tagging, identified four SRP proteins (SRP72, SRP68, SRP54 and SRP19), but no Alu-domain-binding protein homologs. This study highlights the unique features of the trypanosome SRP complex and further supports the hypothesis that the tRNA-like molecule present in this particle may replace the function of the Alu-domain-binding proteins present in many eukaryotic SRP complexes.
Type of Medium:
Online Resource
ISSN:
1477-9137
,
0021-9533
Language:
English
Publisher:
The Company of Biologists
Publication Date:
2005
detail.hit.zdb_id:
219171-4
detail.hit.zdb_id:
1483099-1
SSG:
12
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