BAG6 and SGTA function in the quality control of mislocalised proteins (MLPs) by promoting and inhibiting the degradation of such proteins, respectively. Here (p. 3187), Stephen High and colleagues describe, for the first time, an interaction between the C-terminal domain of Rpn13, a proteasome-associated ubiquitin receptor that facilitates delivery of substrates for degradation, and the tetratricopeptide (TPR) domain of SGTA, and investigate the role of that interaction in the quality control of MLPs. Overexpressed SGTA associated with the proteasome and caused an increase in the levels of OP91, an N-terminal fragment of opsin that acts as an MLP. By contrast, overexpression of both SGTA and the C-terminal domain of Rpn13 decreased the proteasomal association of SGTA, and reduced steady-state levels of OP91 and another model MLP, indicating that when SGTA is titrated away from endogenous Rpn13, it can no longer delay the proteasomal degradation of MLPs. The phenomenon was MLP-specific, as Rpn13 and SGTA expression had no effect on the N-end rule degradation substrate ubiquitin–arginine–GFP. In addition, a point mutation in the TPR domain of SGTA perturbed both its proteasomal recruitment and its ability to increase OP91 levels when overexpressed. In conclusion, this study demonstrates that the BAG6–SGTA-dependent quality control of MLPs occurs, at least in part, at the proteasome as the recruitment of SGTA through Rpn13 is necessary for SGTA to modulate MLP levels.
Rpn13 and SGTA interact in protein quality control
- Split-screen
- Views Icon Views
-
Article Versions Icon
Versions
- Version of Record 01 September 2015
- Share Icon Share
-
Tools Icon
Tools
- Search Site
Rpn13 and SGTA interact in protein quality control. J Cell Sci 1 September 2015; 128 (17): e1702. doi:
Download citation file:
Advertisement
Cited by
Introducing our new Editors
We welcome three new Editors to Journal of Cell Science - Robert Parton, Richa Rikhy and Simon Cook. You can read more about them in the Editorial from our Editor-in-Chief Michael Way.
2024 Journal Meeting 'Diversity and Evolution in Cell Biology'
Registration is open for our 2024 Journal Meeting Diversity and Evolution in Cell Biology, which aims to bring together evolutionary biologists and cell biologists investigating diverse aspects of cellular physiology. Final registration deadline: 3 May 2024.
Workshop: Physics of the Early Embryonic Cell Divisions
Early-career researchers interested in the roles of nuclear lipids, apply now for one of the ten funded places at this Workshop, which will take place 11-14 November 2024. Application deadline: 17 May.
Reasons to submit to Journal of Cell Science
There are many benefits to publishing in Journal of Cell Science - read more about why you should choose JCS or visit our submission page now.