Sorting nexin 5 is localized to a subdomain of the early endosomes and is recruited to the plasma membrane following EGF stimulation

Ana Merino-Trigo, Markus C. Kerr, Fiona Houghton, Anna Lindberg, Christina Mitchell, Rohan D. Teasdale, Paul A. Gleeson

Research output: Contribution to journalArticleResearchpeer-review

49 Citations (Scopus)

Abstract

Sortings nexins are a large family of proteins that contain the phosphoinositide-binding Phox homology (PX) domain. A number of sorting nexins are known to bind to PtdIns(3)P, which mediates their localization to membranes of the endocytic pathway. We show here that sorting nexin 5 (SNX5) can be recruited to two distinct membrane compartments. In non-stimulated cells, the PX domain was independently targeted to endosomal structures and colocalized with full-length SNX5. The membrane binding of the PX domain was inhibited by the PI 3-kinase inhibitor, wortmannin. Although SNX5 colocalized with a fluid-phase marker and was found predominantly within a PtdIns(3)P-rich endosomal domain, very little colocalization was observed between SNX5 and the PtdIns(3)P-binding protein, EEA1. Using liposome-based binding assays, we have shown that the PX domain of SNX5 interacts not only with PtdIns(3)P but also with PtdIns(3,4)P2. In response to EGF stimulation, either the SNX5-PX domain or full-length SNX5 was rapidly recruited to the plasma membrane. The localization of SNX1, which does not bind PtdIns(3,4)P2, was unaffected by EGF signalling. Therefore, SNX5 is localized to a subdomain of the early endosome distinct from EEA1 and, following EGF stimulation and elevation of PtdIns(3,4 P2, is also transiently recruited to the plasma membrane. These results indicate that SNX5 may have functions not only associated with endosomal sorting but also with the phosphoinositide-signalling pathway.

Original languageEnglish
Pages (from-to)6413-6424
Number of pages12
JournalJournal of Cell Science
Volume117
Issue number26
DOIs
Publication statusPublished - 15 Dec 2004
Externally publishedYes

Keywords

  • Early endosomes
  • EGF signalling
  • Phosphoinositides
  • Phox homology domain
  • Sorting nexins

Cite this