1. Spindle-E cycling between nuage and cytoplasm is controlled by Qin and PIWI proteins.
- Author
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Andress A, Bei Y, Fonslow BR, Giri R, Wu Y, Yates JR 3rd, and Carthew RW
- Subjects
- Adenosine Triphosphatases metabolism, Animals, Argonaute Proteins genetics, Argonaute Proteins metabolism, Biological Transport, DNA Transposable Elements physiology, Drosophila Proteins genetics, Drosophila Proteins metabolism, Models, Biological, Nonlinear Dynamics, Peptide Initiation Factors metabolism, Regression Analysis, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism, Argonaute Proteins physiology, Drosophila metabolism, Drosophila Proteins physiology, RNA, Small Interfering metabolism, Ubiquitin-Protein Ligases physiology
- Abstract
Transposable elements (TEs) are silenced in germ cells by a mechanism in which PIWI proteins generate and use PIWI-interacting ribonucleic acid (piRNA) to repress expression of TE genes. piRNA biogenesis occurs by an amplification cycle in microscopic organelles called nuage granules, which are localized to the outer face of the nuclear envelope. One cofactor required for amplification is the helicase Spindle-E (Spn-E). We found that the Spn-E protein physically associates with the Tudor domain protein Qin and the PIWI proteins Aubergine (Aub) and Argonaute3 (Ago3). Spn-E and Qin proteins are mutually dependent for their exit from nuage granules, whereas Spn-E and both Aub and Ago3 are mutually dependent for their entry or retention in nuage. The result is a dynamic cycling of Spn-E and its associated factors in and out of nuage granules. This implies that nuage granules can be considered to be hubs for active, mobile, and transient complexes. We suggest that this is in some way coupled with the execution of the piRNA amplification cycle., (© 2016 Andress et al.)
- Published
- 2016
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