Mitochondria-localized phospholipase A(2), AoPlaA, in Aspergillus oryzae displays phosphatidylethanolamine-specific activity and is involved in the maintenance of mitochondrial phospholipid composition

作者：Kotani Shohei; Izawa Sho; Komai Noriyuki; Takayanagi Ayumi; Arioka Manabu^*

来源：Fungal Genetics and Biology, 2016, 96: 1-11.

DOI：10.1016/j.fgb.2016.09.001

• Cytosolic phospholipase A(2)
• Aspergillus oryzae
• Mitochondria
• Phosphatidylethanolamine

In mammals, cytosolic phospholipases A(2) (cPLA(2)s) play important physiological roles by releasing arachidonic acid, a precursor for bioactive lipid mediators, from the biological membranes. In contrast, fungal cPLA(2)-like proteins are much less characterized and their roles have remained elusive. AoPlaA is a cPLA(2)-like protein in the filamentous fungus Aspergillus oryzae which, unlike mammalian cPLA(2), localizes to mitochondria. In this study, we investigated the biochemical and physiological functions of AoPlaA. Recombinant AoPlaA produced in E. coli displayed Ca2+-independent lipolytic activity. Mass spectrometry analysis demonstrated that AoPlaA displayed PLA(2) activity to phosphatidylethanolamine (PE), but not to other phospholipids, and generated 1-acylated lysoPE. Catalytic site mutants of AoPlaA displayed almost no or largely reduced activity to PE. Consistent with PE-specific activity of AoPlaA, AoplaA-overexpressing strain showed decreased PE content in the mitochondria] fraction. In contrast, AoplaA-disruption strain displayed increased content of cardiolipin. AoplaA-overexpressing strain, but not its counterparts overexpressing the catalytic site mutants, exhibited retarded growth at low temperature, possibly because of the impairment of the mitochondria] function caused by excess degradation of PE. These results suggest that AoPlaA is a novel PE-specific PLA(2) that plays a regulatory role in the maintenance of mitochondria] phospholipid composition.

• 出版日期2016-11