Recruitment of UBPY and ESCRT Exchange Drive HD-PTP-Dependent Sorting of EGFR to the MVB

Ali, Nazim; Zhang, Ling; Taylor, Sandra; Mironov, Alex; Urbé, Sylvie; Woodman, Philip

Abstract

Background
Sorting ubiquitinated epidermal growth factor receptor (EGFR) to the intralumenal vesicles of the multivesicular body requires the coordinated action of several ESCRT complexes. A central question is how EGFR transits vectorially from early, ubiquitin-binding ESCRTs to the final complex, ESCRT-III, such that cargo sequestration is coupled with intralumenal vesicle formation.
Results
We show that the ESCRT accessory protein HD-PTP/PTPN23 associates with EGFR and combines with the deubiquitinating enzyme UBPY/USP8 to transfer EGFR from ESCRT-0 to ESCRT-III and drive EGFR sorting to intralumenal vesicles. HD-PTP binds ESCRT-0 via two interactions with the STAM2 subunit. First, the HD-PTP Bro1 domain binds the core domain of STAM2. This is competed by the ESCRT-III subunit CHMP4B, which binds an overlapping site on HD-PTP Bro1. Second, a proline-rich peptide in HD-PTP binds the SH3 domain of STAM2. Similar proline-rich peptides on UBPY also bind STAM2 SH3 to facilitate EGFR deubiquitination. Hence, locally recruited UBPY would be expected to compete with HD-PTP for STAM2 binding at this second site. Indeed, we show that HD-PTP recruits UBPY to EGFR. Association of UBPY with HD-PTP involves UBPY interacting with HD-PTP-bound CHMP4B, as well as additional interaction(s) between UBPY and HD-PTP.
Conclusions
This study identifies HD-PTP as a central coordinator of the ESCRT pathway for EGFR. Based on these studies, we propose a model whereby the concerted recruitment of CHMP4B and UBPY to HD-PTP and the engagement of UBPY by STAM2 displaces ESCRT-0 from HD-PTP, deubiquitinates EGFR, and releases ESCRT-0 from cargo in favor of ESCRT-III.

Citation

Ali, N., Zhang, L., Taylor, S., Mironov, A., Urbé, S., & Woodman, P. (2013). Recruitment of UBPY and ESCRT Exchange Drive HD-PTP-Dependent Sorting of EGFR to the MVB. Current Biology, 23(6), 453 - 461. https://doi.org/10.1016/j.cub.2013.02.033

• Acceptance Date: Feb 14, 2013
• Online Publication Date: Mar 7, 2013
• Publication Date: Mar 18, 2013
• Publicly Available Date: May 30, 2023
• Journal: Current Biology
• Print ISSN: 0960-9822
• Publisher: Elsevier
• Volume: 23
• Issue: 6
• Pages: 453 - 461
• DOI: https://doi.org/10.1016/j.cub.2013.02.033
• Publisher URL: https://www.cell.com/current-biology/fulltext/S0960-9822(13)00204-2?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982213002042%3Fshowall%3Dtrue#relatedArticles