Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8318364 | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology | 2017 | 6 Pages |
Abstract
Little is known about how the synthesis of mitochondrial phospholipids is integrated into mitochondrial biogenesis in fish or mammals. Glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15) catalyzes the addition of fatty acyl CoA to the sn-1 position of glycerol-3-phosphate, in what is considered the rate-limiting step in phospholipid biosynthesis. Previous studies have shown that mitochondrial volume density increases in oxidative skeletal muscle but not liver of Gasterosteus aculeatus (threespine stickleback) in response to cold acclimation. We hypothesized that maximal activity of GPAT would increase in oxidative skeletal muscle but not liver during cold acclimation, coinciding with mitochondrial biogenesis. GPAT activity was measured in liver and oxidative skeletal (pectoral adductor) muscle of threespine stickleback acclimated to 8 °C or 20 °C. In addition, mRNA levels of enzymes involved in phospholipid synthesis, including cytidine diphosphodiacylglycerol synthase-1 (CDS1), CDS2, GPAT1, GPAT2 and 1-acylglycerol 3-phosphate acyltransferase-2 (AGPAT2), were quantified in liver and pectoral muscle of stickleback harvested during cold acclimation. GPAT activity and transcript levels of AGPAT2 increased in response to cold acclimation in pectoral muscle but not liver. Transcript levels of GPAT1 increased in liver but not pectoral muscle. Overall our results suggest that the activity of GPAT, and possibly AGPAT as well, increase during cold acclimation and may contribute to mitochondrial phospholipid biosynthesis required for mitochondrial biogenesis.
Keywords
PGC-1αElongation factor-1 alphaAGPATLPAATGPATCDP-DAGLPATFAMNRF-1EF-1αG3PmTORperoxisome proliferator-activated receptor gamma coactivator 1-alphaMitochondrial DNAphosphatidic acidlysophosphatidic acidCold acclimationtriacylglycerolTAG یا triacylglycerols diacylglycerolmtDNADAGMitochondrial biogenesisNuclear respiratory factor 1mitochondrial transcription factor AphosphatidylinositolphosphatidylcholinephosphatidylethanolaminePhosphatidylserinelysophosphatidic acid acyltransferaseMechanistic target of rapamycinThreespine sticklebackCdSCardiolipinglycerol 3-phosphate
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Authors
Kelly Keenan, Megan Hoffman, Kristin Dullen, Kristin M. O'Brien,