Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S]
The enzyme 1-acylglycerol-3-phosphate-O-acyltransferase (AGPAT) converts lysophosphatidic acid (LPA) to phosphatidic acid (PA). In this study, we show enzymatic properties, tissue distribution, and subcellular localization of human AGPAT3 and AGPAT5. In cells overexpressing these isoforms, the prote...
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| Format: | Article |
| Language: | English |
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Elsevier
2011-03-01
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| Series: | Journal of Lipid Research |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520409253 |
| _version_ | 1818899253339095040 |
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| author | Sneha S. Prasad Abhimanyu Garg Anil K. Agarwal |
| author_facet | Sneha S. Prasad Abhimanyu Garg Anil K. Agarwal |
| author_sort | Sneha S. Prasad |
| collection | DOAJ |
| description | The enzyme 1-acylglycerol-3-phosphate-O-acyltransferase (AGPAT) converts lysophosphatidic acid (LPA) to phosphatidic acid (PA). In this study, we show enzymatic properties, tissue distribution, and subcellular localization of human AGPAT3 and AGPAT5. In cells overexpressing these isoforms, the proteins were detected in the nuclear envelope and the endoplasmic reticulum. AGPAT5-GFP fusion protein was localized in the mitochondria of both Chinese hamster ovary and human epithelial cervical cancer cells. Using lysates of AD293 cells infected with AGPAT3 and AGPAT5 recombinant adenovirus, we show that AGPAT3 and AGPAT5 proteins have AGPAT activity. Both the isoforms have similar apparent Vmax of 6.35 and 2.42 nmol/min/mg protein, respectively, for similar LPA. The difference between the two isoforms is in their use of additional lysophospholipids. AGPAT3 shows significant esterification of lysophosphatidylinositol (LPI) in the presence of C20:4 fatty acid, whereas AGPAT5 demonstrates significant acyltransferase activity toward lysophosphatidylethanolamine (LPE) in the presence of C18:1 fatty acid. The AGPAT3 mRNA is ubiquitously expressed in human tissues with several-fold differences in the expression pattern compared with the closely related AGPAT4. In summary, we show that in the presence of different fatty acids, AGPAT3 and AGPAT5 prefer different lysophospholipids as acyl acceptors. More importantly, localization of overexpressed AGPAT5 (this study) as well as GPAT1 and 2 (previous studies) in mitochondria supports the idea that the mitochondria might be capable of synthesizing some of their own glycerophospholipids. |
| first_indexed | 2024-12-19T19:45:02Z |
| format | Article |
| id | doaj.art-047c287daf904acbb1c1e99582b9434a |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-19T19:45:02Z |
| publishDate | 2011-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-047c287daf904acbb1c1e99582b9434a2022-12-21T20:08:09ZengElsevierJournal of Lipid Research0022-22752011-03-01523451462Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S]Sneha S. Prasad0Abhimanyu Garg1Anil K. Agarwal2Division of Nutrition and Metabolic Diseases, Department of Internal Medicine and Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TXDivision of Nutrition and Metabolic Diseases, Department of Internal Medicine and Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TXTo whom correspondence should be addressed. Anil.Agarwal@UTSouthwestern.edu; Division of Nutrition and Metabolic Diseases, Department of Internal Medicine and Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TXThe enzyme 1-acylglycerol-3-phosphate-O-acyltransferase (AGPAT) converts lysophosphatidic acid (LPA) to phosphatidic acid (PA). In this study, we show enzymatic properties, tissue distribution, and subcellular localization of human AGPAT3 and AGPAT5. In cells overexpressing these isoforms, the proteins were detected in the nuclear envelope and the endoplasmic reticulum. AGPAT5-GFP fusion protein was localized in the mitochondria of both Chinese hamster ovary and human epithelial cervical cancer cells. Using lysates of AD293 cells infected with AGPAT3 and AGPAT5 recombinant adenovirus, we show that AGPAT3 and AGPAT5 proteins have AGPAT activity. Both the isoforms have similar apparent Vmax of 6.35 and 2.42 nmol/min/mg protein, respectively, for similar LPA. The difference between the two isoforms is in their use of additional lysophospholipids. AGPAT3 shows significant esterification of lysophosphatidylinositol (LPI) in the presence of C20:4 fatty acid, whereas AGPAT5 demonstrates significant acyltransferase activity toward lysophosphatidylethanolamine (LPE) in the presence of C18:1 fatty acid. The AGPAT3 mRNA is ubiquitously expressed in human tissues with several-fold differences in the expression pattern compared with the closely related AGPAT4. In summary, we show that in the presence of different fatty acids, AGPAT3 and AGPAT5 prefer different lysophospholipids as acyl acceptors. More importantly, localization of overexpressed AGPAT5 (this study) as well as GPAT1 and 2 (previous studies) in mitochondria supports the idea that the mitochondria might be capable of synthesizing some of their own glycerophospholipids.http://www.sciencedirect.com/science/article/pii/S00222275204092531-acylglycerol-3-phosphate-O-acyltransferaseLPAATacyltransferasephospholipidlipodystrophy |
| spellingShingle | Sneha S. Prasad Abhimanyu Garg Anil K. Agarwal Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S] Journal of Lipid Research 1-acylglycerol-3-phosphate-O-acyltransferase LPAAT acyltransferase phospholipid lipodystrophy |
| title | Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S] |
| title_full | Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S] |
| title_fullStr | Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S] |
| title_full_unstemmed | Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S] |
| title_short | Enzymatic activities of the human AGPAT isoform 3 and isoform 5: localization of AGPAT5 to mitochondria[S] |
| title_sort | enzymatic activities of the human agpat isoform 3 and isoform 5 localization of agpat5 to mitochondria s |
| topic | 1-acylglycerol-3-phosphate-O-acyltransferase LPAAT acyltransferase phospholipid lipodystrophy |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520409253 |
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