cPLA2gamma was identified as an ortholog of cPLA2alpha, which is a key enzyme in eicosanoid production. cPLA2gamma was reported to be located in endoplasmic reticulum (ER) and mitochondria and to have lysophospholipase activity beside phospholipase A2 (PLA2) activity. However, subcellular localization, mechanism of membrane binding, regulation and physiological function have not been fully established. In the present study, we examined the subcellular localization and enzymatic properties of cPLA2gamma with C-terminal FLAG-tag. We found that cPLA2gamma was located not only in ER but also mitochondria even in the absence of the prenylation. Purified recombinant cPLA2gamma catalyzed an acyltransferase reaction from one molecule of lysophosphatidylcholine (LPC) to another, forming phosphatidylcholine (PC). LPC or lysophosphatidylethanolamine acted as acyl donor and acceptor, but lysophosphatidylserine, lysophosphatidylinositol and lysophosphatidic acid (LPA) did not. PC and phosphatidylethanolamine (PE) also acted as weak acyl donors. Reaction conditions changed the balance of lysophospholipase and transacylation activities, with addition of LPA/PA, pH>8, and elevated temperature markedly increasing transacylation activity; this suggests that lysophospholipase/transacylation activities of cPLA2gamma may be regulated by various factors. As lysophospholipids are known to accumulate in ischemia heart and to induce arryhthmia, the cPLA2gamma that is abundant in heart may have a protective role through clearance of lysophospholipids by its transacylation activity.
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http://dx.doi.org/10.1016/j.bbalip.2009.05.008 | DOI Listing |
Nat Chem Biol
January 2025
Zhejiang Key Laboratory of Molecular Cancer Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China.
RAF protein kinases are major RAS effectors that function by phosphorylating MEK. Although all three RAF isoforms share a conserved RAS binding domain and bind to GTP-loaded RAS, only ARAF uniquely enhances RAS activity. Here we uncovered the molecular basis of ARAF in regulating RAS activation.
View Article and Find Full Text PDFMethods Enzymol
January 2025
Department of Chemistry, Washington University in St. Louis, MO, United States. Electronic address:
Adenosine-to-inosine (A-to-I) editing, catalyzed by adenosine deaminases acting on RNA (ADARs), is a prevalent post-transcriptional modification that is vital for numerous biological functions. Given that this modification impacts global gene expression, RNA localization, and innate cellular immunity, dysregulation of A-to-I editing has unsurprisingly been linked to a variety of cancers and other diseases. However, our current understanding of the underpinning mechanisms that connect dysregulated A-to-I editing and disease processes remains limited.
View Article and Find Full Text PDFImmunohorizons
January 2025
Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, United States.
Antibody (Ab) crosslinking of HLA class II (HLA II) molecules on the surface of endothelial cells (ECs) triggers proliferative and prosurvival intracellular signaling, which are implicated in promoting chronic Ab-mediated rejection (cAMR). Despite the importance of cAMR in transplant medicine, the mechanisms involved remain incompletely understood. Here, we examined the regulation of yes-associated protein (YAP) nuclear cytoplasmic localization and phosphorylation in human ECs challenged with Abs that bind HLA II, which are strongly associated with cAMR.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:
Under salt stress, plasma membrane proteins regulate ion homeostasis and the balance between reactive oxygen species (ROS). In this study, we investigated the functions of two small membrane proteins-MsRCI2B (tailless) and MsRCI2E (tailed)-encoded by the RCI2 (Rare Cold Inducible 2) gene family in Medicago sativa (alfalfa). We identified the distinct subcellular localization and expression patterns of these proteins under salt stress.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
Department of Pharmacy, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China. Electronic address:
Nitric oxide (NO) has been highlighted as a key gaseous signaling molecule in the body, playing a central role in various physiological and pathological processes. However, a comprehensive analysis of NO metabolism dynamics in living cells remains a significant challenge. To address this, we have developed and characterized a novel genetically encoded NO fluorescence sensor, GefiNO, to investigate NO metabolism dynamics in living cells and subcellular organelles.
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