The cytosolic phospholipase a2α n-terminal c2 domain binds and oligomerizes on membranes with positive curvature

Katherine E. Ward, Ranjan Sengupta, James P. Ropa, Souad Amiar, Robert V. Stahelin

Research output: Contribution to journalArticle

Abstract

Group IV phospholipase A2α (cPLA2α) regulates the production of prostaglandins and leukotrienes via the formation of arachidonic acid from membrane phospholipids. The targeting and membrane binding of cPLA2α to the Golgi involves the N-terminal C2 domain, whereas the catalytic domain produces arachidonic acid. Although most studies of cPLA2α concern its catalytic activity, it is also linked to homeostatic processes involving the generation of vesicles that traffic material from the Golgi to the plasma membrane. Here we investigated how membrane curvature influences the homeostatic role of cPLA2α in vesicular trafficking. The cPLA2α C2 domain is known to induce changes in positive membrane curvature, a process which is dependent on cPLA2α membrane penetration. We showed that cPLA2α undergoes C2 domain-dependent oligomerization on membranes in vitro and in cells. We found that the association of the cPLA2α C2 domain with membranes is limited to membranes with positive curvature, and enhanced C2 domain oligomerization was observed on vesicles ~50 nm in diameter. We demonstrated that the cPLA2α C2 domain localizes to cholesterol enriched Golgi-derived vesicles independently of cPLA2α catalytic activity. Moreover, we demonstrate the C2 domain selectively localizes to lipid droplets whereas the full-length enzyme to a much lesser extent. Our results therefore provide novel insight into the molecular forces that mediate C2 domain-dependent membrane localization in vitro and in cells.

Original languageEnglish (US)
Article number647
JournalBiomolecules
Volume10
Issue number4
DOIs
StatePublished - Apr 2020
Externally publishedYes

Keywords

  • C2 domain
  • Cytosolic phospholipase Aα (cPLAα)
  • Electron microscopy
  • Golgi
  • Membrane bending
  • Membrane curvature
  • Oligomerization

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

Fingerprint Dive into the research topics of 'The cytosolic phospholipase a<sub>2</sub>α n-terminal c2 domain binds and oligomerizes on membranes with positive curvature'. Together they form a unique fingerprint.

  • Cite this