Publications

• Two abscisic acid responsive plastid lipase genes involved in jasmonic acid biosynthesis in Arabidopsis thaliana.

  Wang K., Guo Q., Froehlich J.E., Hersh H.L., Zienkiewicz A., Howe G.A., Benning C.

  Chloroplast membranes with their unique lipid composition are crucial for photosynthesis. Maintenance of the chloroplast membranes requires finely tuned lipid anabolic and catabolic reactions. Despite the presence of a large number of predicted lipid-degrading enzymes in the chloroplasts, their bi ... >> More

  Chloroplast membranes with their unique lipid composition are crucial for photosynthesis. Maintenance of the chloroplast membranes requires finely tuned lipid anabolic and catabolic reactions. Despite the presence of a large number of predicted lipid-degrading enzymes in the chloroplasts, their biological functions remain largely unknown. Recently, we described PLASTID LIPASE1 (PLIP1), a plastid phospholipase A₁ that contributes to seed oil biosynthesis. The <i>Arabidopsis thaliana</i> genome encodes two putative PLIP1 paralogs, which we designated PLIP2 and PLIP3. PLIP2 and PLIP3 are also present in the chloroplasts, but likely with different subplastid locations. In vitro analysis indicated that both are glycerolipid A₁ lipases. In vivo, PLIP2 prefers monogalactosyldiacylglycerol as substrate and PLIP3 phosphatidylglycerol. Overexpression of <i>PLIP2</i> or <i>PLIP3</i> severely reduced plant growth and led to accumulation of the bioactive form of jasmonate and related oxylipins. Genetically blocking jasmonate perception restored the growth of the <i>PLIP2/3</i>-overexpressing plants. The expression of <i>PLIP2</i> and <i>PLIP3</i>, but not <i>PLIP1</i>, was induced by abscisic acid (ABA), and <i>plip1 plip2 plip3</i> triple mutants exhibited compromised oxylipin biosynthesis in response to ABA. The <i>plip</i> triple mutants also showed hypersensitivity to ABA. We propose that PLIP2 and PLIP3 provide a mechanistic link between ABA-mediated abiotic stress responses and oxylipin signaling. << Less

  Plant Cell 30:1006-1022(2018) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.

• Structure/Function relationships of adipose phospholipase A2 containing a cys-his-his catalytic triad.

  Pang X.Y., Cao J., Addington L., Lovell S., Battaile K.P., Zhang N., Rao J.L., Dennis E.A., Moise A.R.

  Adipose phospholipase A(2) (AdPLA or Group XVI PLA(2)) plays an important role in the onset of obesity by suppressing adipose tissue lipolysis. As a consequence, AdPLA-deficient mice are resistant to obesity induced by a high fat diet or leptin deficiency. It has been proposed that AdPLA mediates ... >> More

  Adipose phospholipase A(2) (AdPLA or Group XVI PLA(2)) plays an important role in the onset of obesity by suppressing adipose tissue lipolysis. As a consequence, AdPLA-deficient mice are resistant to obesity induced by a high fat diet or leptin deficiency. It has been proposed that AdPLA mediates its antilipolytic effects by catalyzing the release of arachidonic acid. Based on sequence homology, AdPLA is part of a small family of acyltransferases and phospholipases related to lecithin:retinol acyltransferase (LRAT). To better understand the enzymatic mechanism of AdPLA and LRAT-related proteins, we solved the crystal structure of AdPLA. Our model indicates that AdPLA bears structural similarity to proteins from the NlpC/P60 family of cysteine proteases, having its secondary structure elements configured in a circular permutation of the classic papain fold. Using both structural and biochemical evidence, we demonstrate that the enzymatic activity of AdPLA is mediated by a distinctive Cys-His-His catalytic triad and that the C-terminal transmembrane domain of AdPLA is required for the interfacial catalysis. Analysis of the enzymatic activity of AdPLA toward synthetic and natural substrates indicates that AdPLA displays PLA(1) in addition to PLA(2) activity. Thus, our results provide insight into the enzymatic mechanism and biochemical properties of AdPLA and LRAT-related proteins and lead us to propose an alternate mechanism for AdPLA in promoting adipose tissue lipolysis that is not contingent on the release of arachidonic acid and that is compatible with its combined PLA(1)/A(2) activity. << Less

  J. Biol. Chem. 287:35260-35274(2012) [PubMed] [EuropePMC]

  This publication is cited by 9 other entries.