Essential role of cytoplasmic sequences for cell-surface sorting of the lectin-like oxidized LDL receptor-1 (LOX-1)

Mingyi Chen, Tatsuya Sawamura

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Lectin-like oxidized LDL receptor-1 (LOX-1) is an oxidized low-density lipoprotein (OxLDL) receptor found in endothelial cells and a member of the natural killer (NK) receptor gene complex. Here, we demonstrate that the ability of LOX-1 binding to OxLDL distinguishes it from other NK receptors. Domain swapping of the lectin-like domain between LOX-1 and the NK cell receptors CD94, NKG2D, and LY-49A demonstrated the crucial role of this domain for recognition of OxLDL by LOX-1, but not for the correct cell-surface sorting of LOX-1. Using LOX-1 GFP fusion constructs, we find that the combination of cytoplasmic and transmembrane domains of LOX-1 is sufficient to target the chimeric protein to the cell-surface. Using N-terminal deletions we determined that the correct cell-surface localization is dependent on a positively charged motif present in the cytosolic juxtamembrane region of LOX-1. Furthermore, the extracellular localization of the LOX-1 C-terminus is disrupted when we mutated the cytoplasmic basic amino acids, Lys-22, Lys-23 and Lys-25 to Glu. Collectively, these results indicate that the N-terminal cytoplasmic domain of LOX-1 determines the correct expression of the lectin domain on the cell-surface.

Original languageEnglish (US)
Pages (from-to)553-561
Number of pages9
JournalJournal of Molecular and Cellular Cardiology
Volume39
Issue number3
DOIs
StatePublished - Sep 2005

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Keywords

  • Cell-surface sorting
  • Integral membrane protein topology
  • Lectin-like oxidized LDL receptor-1

ASJC Scopus subject areas

  • Molecular Biology
  • Cardiology and Cardiovascular Medicine

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