Ping Zhou

Studies involving the cloning and disruption of the gene for acyl-CoA:diacylglycerol acyltransferase (DGAT) have shown that alternative mechanisms exist for triglyceride synthesis. In this study, we cloned and characterized a second mammalian DGAT, DGAT2, which was identified by its homology to a DGAT in the fungus Mortierella rammaniana. DGAT2 is a member of a gene family that has no homology with DGAT1 and includes several mouse and human homologues that are candidates for additional DGAT genes. The expression of DGAT2 in insect cells stimulated triglyceride synthesis 6-fold in assays with cellular membranes, and DGAT2 activity was dependent on the presence of fatty acyl-CoA and diacylglycerol, indicating that this protein is a DGAT. Activity was not observed for acyl acceptors other than diacylglycerol. DGAT2 activity was inhibited by a high concentration (100 mm) of MgCl(2) in an in vitro assay, a characteristic that distinguishes DGAT2 from DGAT1. DGAT2 is expressed in many tissues with high expression levels in the liver and white adipose tissue, suggesting that it may play a significant role in mammalian triglyceride metabolism.

Modern sugarcanes are polyploid interspecific hybrids, combining high sugar content from Saccharum officinarum with hardiness, disease resistance and ratooning of Saccharum spontaneum. Sequencing of a haploid S. spontaneum, AP85-441, facilitated the assembly of 32 pseudo-chromosomes comprising 8 homologous groups of 4 members each, bearing 35,525 genes with alleles defined. The reduction of basic chromosome number from 10 to 8 in S. spontaneum was caused by fissions of 2 ancestral chromosomes followed by translocations to 4 chromosomes. Surprisingly, 80% of nucleotide binding site-encoding genes associated with disease resistance are located in 4 rearranged chromosomes and 51% of those in rearranged regions. Resequencing of 64 S. spontaneum genomes identified balancing selection in rearranged regions, maintaining their diversity. Introgressed S. spontaneum chromosomes in modern sugarcanes are randomly distributed in AP85-441 genome, indicating random recombination among homologs in different S. spontaneum accessions. The allele-defined Saccharum genome offers new knowledge and resources to accelerate sugarcane improvement.

Understanding the genetic changes underlying phenotypic variation in sheep (Ovis aries) may facilitate our efforts towards further improvement. Here, we report the deep resequencing of 248 sheep including the wild ancestor (O. orientalis), landraces, and improved breeds. We explored the sheep variome and selection signatures. We detected genomic regions harboring genes associated with distinct morphological and agronomic traits, which may be past and potential future targets of domestication, breeding, and selection. Furthermore, we found non-synonymous mutations in a set of plausible candidate genes and significant differences in their allele frequency distributions across breeds. We identified PDGFD as a likely causal gene for fat deposition in the tails of sheep through transcriptome, RT-PCR, qPCR, and Western blot analyses. Our results provide insights into the demographic history of sheep and a valuable genomic resource for future genetic studies and improved genome-assisted breeding of sheep and other domestic animals.

The synthesis and storage of neutral lipids in lipid droplets is a fundamental property of eukaryotic cells, but the spatial organization of this process is poorly understood. Here we examined the intracellular localization of acyl-CoA:diacylglycerol acyltransferase 2 (DGAT2), an enzyme that catalyzes the final step of triacylglycerol (TG) synthesis in eukaryotes. We found that DGAT2 expressed in cultured cells localizes to the endoplasmic reticulum (ER) under basal conditions. After providing oleate to drive TG synthesis, DGAT2 also localized to near the surface of lipid droplets, where it co-localized with mitochondria. Biochemical fractionation revealed that DGAT2 is present in mitochondria-associated membranes, specialized domains of the ER that are highly enriched in lipid synthetic enzymes and interact tightly with mitochondria. The interaction of DGAT2 with mitochondria depended on 67 N-terminal amino acids of DGAT2, which are not conserved in family members that have different catalytic functions. This targeting signal was sufficient to localize a red fluorescent protein to mitochondria. A highly conserved, positively charged, putative mitochondrial targeting signal was identified in murine DGAT2 between amino acids 61 and 66. Thus, DGAT2, an ER-resident transmembrane domain-containing enzyme, is also found in mitochondria-associated membranes, where its N terminus may promote its association with mitochondria. The synthesis and storage of neutral lipids in lipid droplets is a fundamental property of eukaryotic cells, but the spatial organization of this process is poorly understood. Here we examined the intracellular localization of acyl-CoA:diacylglycerol acyltransferase 2 (DGAT2), an enzyme that catalyzes the final step of triacylglycerol (TG) synthesis in eukaryotes. We found that DGAT2 expressed in cultured cells localizes to the endoplasmic reticulum (ER) under basal conditions. After providing oleate to drive TG synthesis, DGAT2 also localized to near the surface of lipid droplets, where it co-localized with mitochondria. Biochemical fractionation revealed that DGAT2 is present in mitochondria-associated membranes, specialized domains of the ER that are highly enriched in lipid synthetic enzymes and interact tightly with mitochondria. The interaction of DGAT2 with mitochondria depended on 67 N-terminal amino acids of DGAT2, which are not conserved in family members that have different catalytic functions. This targeting signal was sufficient to localize a red fluorescent protein to mitochondria. A highly conserved, positively charged, putative mitochondrial targeting signal was identified in murine DGAT2 between amino acids 61 and 66. Thus, DGAT2, an ER-resident transmembrane domain-containing enzyme, is also found in mitochondria-associated membranes, where its N terminus may promote its association with mitochondria. Most eukaryotic cells can synthesize neutral lipids, such as triacylglycerols (TGs) 2The abbreviations used are: TG, triacylglycerol; ADRP, adipose differentiation-related protein; BODIPY 493/503, 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene; DGAT, acyl-CoA:diacylglycerol acyltransferase; ER, endoplasmic reticulum; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; GFP, green fluorescent protein; HSP70, heat-shock protein 70; MAM, mitochondria-associated membranes; MGAT, monoacylglycerol acyltransferase; 18:1, oleate; RFP, monomeric red fluorescent protein; PBS, phosphate-buffered saline.2The abbreviations used are: TG, triacylglycerol; ADRP, adipose differentiation-related protein; BODIPY 493/503, 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene; DGAT, acyl-CoA:diacylglycerol acyltransferase; ER, endoplasmic reticulum; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; GFP, green fluorescent protein; HSP70, heat-shock protein 70; MAM, mitochondria-associated membranes; MGAT, monoacylglycerol acyltransferase; 18:1, oleate; RFP, monomeric red fluorescent protein; PBS, phosphate-buffered saline. and sterol esters, and store them in cytosolic lipid droplets. Yet, a molecular understanding of this process and how it is spatially organized is lacking. For example, lipid substrates for TG synthesis (fatty acids and glycerolipid precursors) are found in the cytoplasm and membranes, energy for activating fatty acids (by converting to fatty acyl-CoA) comes from mitochondria, and the enzymes that catalyze TG formation are primarily found in the mitochondria and endoplasmic reticulum (ER). How the cell orchestrates this complex anabolic process to maximize lipid synthesis and storage during times of substrate excess is poorly understood. In most cells, TG synthesis occurs via the glycerol 3-phosphate (Kennedy) pathway and involves multiple enzymatic reactions in different subcellular compartments (1Coleman R.A. Lee D.P. Prog. Lipid Res. 2004; 43: 134-176Crossref PubMed Scopus (705) Google Scholar). The fatty acids for TG synthesis must first be “activated” by acyl-CoA synthases, a family of enzymes that localize to membranes of different compartments, including the ER, mitochondria, and plasma membrane (2Lewin T.M. Kim J.-H. Granger D.A. Vance J.E. Coleman R.A. J. Biol. Chem. 2001; 276: 24674-24679Abstract Full Text Full Text PDF PubMed Scopus (225) Google Scholar), and utilize ATP to ligate CoA to the fatty acyl chain. Next, these fatty acids enter the Kennedy pathway of glycerolipid synthesis, in which the first two reactions occur in both the ER and mitochondria. In the first reaction, glycerol 3-phosphate and a fatty acyl-CoA are combined to yield lysophosphatidic acid through the actions of glycerol-3-phosphate acyltransferase enzymes (1Coleman R.A. Lee D.P. Prog. Lipid Res. 2004; 43: 134-176Crossref PubMed Scopus (705) Google Scholar, 3Gimeno R.E. Cao J. J. Lipid Res. 2008; 49: 2079-2088Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar). In the second reaction, 1-acylglycerol-3-phosphate O-acyltransferase enzymes catalyze the esterification of lysophosphatidic acid with fatty acyl-CoA to form phosphatidic acid (1Coleman R.A. Lee D.P. Prog. Lipid Res. 2004; 43: 134-176Crossref PubMed Scopus (705) Google Scholar, 4Shindou H. Shimizu T. J. Biol. Chem. 2009; 284: 1-5Abstract Full Text Full Text PDF PubMed Scopus (308) Google Scholar). Next, phosphatidic acid is dephosphorylated at membrane surfaces by phosphatidate phosphatase to yield diacylglycerol (1Coleman R.A. Lee D.P. Prog. Lipid Res. 2004; 43: 134-176Crossref PubMed Scopus (705) Google Scholar, 5Han G.S. Wu W.I. Carman G.M. J. Biol. Chem. 2006; 281: 9210-9218Abstract Full Text Full Text PDF PubMed Scopus (421) Google Scholar, 6Jamal Z. Martin A. Gomez-Muñoz A. Brindley D.N. J. Biol. Chem. 1991; 266: 2988-2996Abstract Full Text PDF PubMed Google Scholar). All these steps are highly organized spatially, which is likely to be important for the efficiency of the pathway. The final reaction of TG synthesis is catalyzed by acyl-CoA: diacylglycerol acyltransferase (DGAT) enzymes (7Bell R.M. Coleman R.A. Annu. Rev. Biochem. 1980; 49: 459-487Crossref PubMed Scopus (455) Google Scholar, 8Brindley D.N. Vance D.E. Vance J.E. Biochemistry of Lipids, Lipoproteins and Membranes. Elsevier, Amsterdam1991: 171-203Google Scholar, 9Gunstone F.D. Harwood J.L. Padley F.B. The Lipid Handbook. Chapman & Hall, London1994: 646-651Google Scholar). The two mammalian DGATs, DGAT1 and DGAT2 (10Cases S. Smith S.J. Zheng Y.-W. Myers H.M. Lear S.R. Sande E. Novak S. Collins C. Welch C.B. Lusis A.J. Erickson S.K. Farese Jr., R.V. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 13018-13023Crossref PubMed Scopus (868) Google Scholar, 11Cases S. Stone S.J. Zhou P. Yen E. Tow B. Lardizabal K.D. Voelker T. Farese Jr., R.V. J. Biol. Chem. 2001; 276: 38870-38876Abstract Full Text Full Text PDF PubMed Scopus (630) Google Scholar), which are encoded by genes of different families, have distinct roles in TG synthesis (12Yen C.L. Stone S.J. Koliwad S. Harris C. Farese Jr., R.V. J. Lipid Res. 2008; 49: 2283-2301Abstract Full Text Full Text PDF PubMed Scopus (714) Google Scholar). DGAT2 is the major TG biosynthetic enzyme in eukaryotes. Dgat2-deficient mice die shortly after birth and are almost completely devoid of TG (13Stone S.J. Myers H.M. Watkins S.M. Brown B.E. Feingold K.R. Elias P.M. Farese Jr., R.V. J. Biol. Chem. 2004; 279: 11767-11776Abstract Full Text Full Text PDF PubMed Scopus (462) Google Scholar), indicating an essential requirement for DGAT2. Catalysis of TG synthesis is conserved in the DGAT2 gene family, with functional orthologs in many species, including Dga1p in Saccharomyces cerevisiae, which contributes to a major portion of TG synthesis (14Oelkers P. Cromley D. Padamsee M. Billheimer J.T. Sturley S.L. J. Biol. Chem. 2002; 277: 8877-8881Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar, 15Sandager L. Gustavsson M.H. Stahl U. Dahlqvist A. Wiberg E. Banas A. Lenman M. Ronne H. Stymne S. J. Biol. Chem. 2002; 277: 6478-6482Abstract Full Text Full Text PDF PubMed Scopus (399) Google Scholar, 16Sorger D. Daum G. J. Bacteriol. 2002; 184: PubMed Scopus Google Scholar). is the intracellular localization of is present in (7Bell R.M. Coleman R.A. Annu. Rev. Biochem. 1980; 49: 459-487Crossref PubMed Scopus (455) Google Scholar, A. Prog. Lipid Res. PubMed Scopus Google Scholar, Kennedy J. Biol. Chem. Full Text PDF PubMed Google Scholar), but in not between DGAT1 and DGAT2. A fluorescent protein expressed in cells localized to the ER H. H. M. S. H. H. Biochem. Res. PubMed Scopus Google Scholar), and Dga1p in S. localizes to the ER and lipid droplets D. Daum G. J. Bacteriol. 2002; 184: PubMed Scopus Google Scholar). DGAT1 and DGAT2 expressed in cells localized primarily to the ER J. L. J. Lipid Res. Full Text Full Text PDF PubMed Scopus Google Scholar). A of the subcellular of DGAT1 and DGAT2 in cells revealed that the enzymes are in of the ER S.K. S.J. 2006; PubMed Scopus (421) Google Scholar). Most DGAT2 was to with lipid droplets in cultured L. C. C. 2008; PubMed Scopus Google Scholar). a step a understanding of the organization of that to TG synthesis and we the subcellular localization of murine DGAT2 in mammalian of DGAT2, and with N-terminal For of DGAT1 and DGAT2 in cells, DGAT1 and DGAT2 the The DGAT1 with a and DGAT2 with an N-terminal and DGAT2 DGAT2 as a in reactions with the The was by a of DGAT2 acid to the N terminus of monomeric from R.E. G.S. D.A. Proc. Natl. Acad. Sci. U. S. A. 2002; PubMed Scopus Google Scholar, R.E. 2004; PubMed Scopus Google Scholar). and by as a in reactions and the All to the of the and cells cultured in with in a with For of was with of in of for at The was to a of and cells at After cells and used for subcellular fractionation cells DGAT1 and DGAT2 as (13Stone S.J. Myers H.M. Watkins S.M. Brown B.E. Feingold K.R. Elias P.M. Farese Jr., R.V. J. Biol. Chem. 2004; 279: 11767-11776Abstract Full Text Full Text PDF PubMed Scopus (462) Google Scholar). cells with PBS, by and by cells, the was in of and and through a and by at for The membrane of used for in as (13Stone S.J. Myers H.M. Watkins S.M. Brown B.E. Feingold K.R. Elias P.M. Farese Jr., R.V. J. Biol. Chem. 2004; 279: 11767-11776Abstract Full Text Full Text PDF PubMed Scopus (462) Google Scholar). In cell with DGAT1 to The was by by on to membranes and with the protein and with the to by with of cells in with of and of after cells and and for In cells with oleate to fatty for to promote lipid with in for and with in for with in for to and at for with the and that an mitochondrial protein; a from of For cells with and After with cells to and for All at lipid droplets, cells with the neutral lipid BODIPY during with In mitochondria by cells DGAT2 with for as and first with and with the lipid adipose differentiation-related protein cells with an protein from C. of and DGAT2. as and DGAT2 was by cells with and was on with a of and to with a with and Lipid from 2 to cells F.D. Harwood J.L. Padley F.B. The Lipid Handbook. Chapman & Hall, London1994: 646-651Google Scholar, S. Smith S.J. Zheng Y.-W. Myers H.M. Lear S.R. Sande E. Novak S. Collins C. Welch C.B. Lusis A.J. Erickson S.K. Farese Jr., R.V. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 13018-13023Crossref PubMed Scopus (868) Google Scholar, 11Cases S. Stone S.J. Zhou P. Yen E. Tow B. Lardizabal K.D. Voelker T. Farese Jr., R.V. J. Biol. Chem. 2001; 276: 38870-38876Abstract Full Text Full Text PDF PubMed Scopus (630) Google Scholar, C.L. Stone S.J. Koliwad S. Harris C. Farese Jr., R.V. J. Lipid Res. 2008; 49: 2283-2301Abstract Full Text Full Text PDF PubMed Scopus (714) Google Scholar, S.J. Myers H.M. Watkins S.M. Brown B.E. Feingold K.R. Elias P.M. Farese Jr., R.V. J. Biol. Chem. 2004; 279: 11767-11776Abstract Full Text Full Text PDF PubMed Scopus (462) Google Scholar, P. Cromley D. Padamsee M. Billheimer J.T. Sturley S.L. J. Biol. Chem. 2002; 277: 8877-8881Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar, 15Sandager L. Gustavsson M.H. Stahl U. Dahlqvist A. Wiberg E. Banas A. Lenman M. Ronne H. Stymne S. J. Biol. Chem. 2002; 277: 6478-6482Abstract Full Text Full Text PDF PubMed Scopus (399) Google Scholar, 16Sorger D. Daum G. J. Bacteriol. 2002; 184: PubMed Scopus Google Scholar, A. Prog. Lipid Res. PubMed Scopus Google lipid with the The of lipid droplets cell R.E. Cao J. J. Lipid Res. 2008; 49: 2079-2088Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar, 4Shindou H. Shimizu T. J. Biol. Chem. 2009; 284: 1-5Abstract Full Text Full Text PDF PubMed Scopus (308) Google Scholar, 5Han G.S. Wu W.I. Carman G.M. J. Biol. Chem. 2006; 281: 9210-9218Abstract Full Text Full Text PDF PubMed Scopus (421) Google was with S.J. 2004; Scholar). the of cells in mitochondria-associated membranes and mitochondrial from cultured cells as S.J. Vance J.E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). in and with in a The was at for to and and the was at for to the mitochondria The was at for in a at to which in The mitochondria was in of and on of of and and for at A mitochondria was from the with and by at for The mitochondrial was in from the as a the mitochondria. with and at for The was at for in a in are as between by the by the DGAT2 to the ER and with Lipid the subcellular localization of murine DGAT2, we expressed N-terminal DGAT2 in cells and its with that of a ER membrane basal DGAT2 a ER and co-localized with DGAT2 and also in the cells DGAT2 with oleate for both DGAT2 and at the surface of that to be lipid droplets but not DGAT2, identified as a lipid protein G. L. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar, S. M. T. T. H. T. M. J. Biochem. 2006; PubMed Scopus Google Scholar, S. M. T. C. A. 2006; PubMed Scopus Google Scholar, Z. J. PubMed Scopus Google Scholar). in cells DGAT2 and with oleate for was not to cells not indicating that the enzymatic not the in that the lipid droplets, we the localization of DGAT2 with that of a lipid cells with DGAT2 and a that an In cells that with DGAT2 and co-localized at the surfaces of lipid droplets We also cells with the neutral lipid BODIPY In cells, DGAT2 a localization lipid droplets, which in the with by L. C. C. 2008; PubMed Scopus Google Scholar), also that DGAT2 with lipid droplets in In that a at the N of DGAT2 its localization to the ER, DGAT2 localized to lipid droplets after lipid that an with DGAT2 This was not the for DGAT2 with the N-terminal that was used in DGAT2 and DGAT2 ER and present lipid droplets in cells not We with DGAT2. DGAT2, the lipid DGAT1 and an and not to a lipid droplets in cells and We also examined the and of lipid droplets by cells DGAT2, and that with oleate for lipid of cells with oleate is in Lipid droplets in cells DGAT1 in to cells but and In lipid droplets in cells DGAT2 a cells and a in the of lipid droplets, which from of droplets to lipid droplets. This is to the in cells DGAT1 and DGAT2 (13Stone S.J. Myers H.M. Watkins S.M. Brown B.E. Feingold K.R. Elias P.M. Farese Jr., R.V. J. Biol. Chem. 2004; 279: 11767-11776Abstract Full Text Full Text PDF PubMed Scopus (462) Google Scholar), where cells lipid droplets, cells a cytosolic lipid of lipid from cells DGAT2, and that with oleate for in a of DGAT2 with after Lipid the localization of DGAT2 to that of such as mitochondria and the For mitochondria, we used the and is a protein with an that in the mitochondria and completely with In cells with DGAT2 not with mitochondria a for both and and co-localized with DGAT2 A and cells with oleate to promote lipid mitochondria a lipid droplets and co-localized almost completely with DGAT2 A and the the lipid surface was for mitochondria, we examined the subcellular of the under conditions. mitochondria, not the lipid surface of cells DGAT2 and a in both the and of oleate was not in cells DGAT1 not DGAT2 in is enriched in Z. M.H. Vance J.E. J. Biol. Chem. Full Text PDF PubMed Google Scholar), a of the ER that with mitochondria and is enriched with lipid synthetic enzymes S.J. Vance J.E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, Z. M.H. Vance J.E. J. Biol. Chem. Full Text PDF PubMed Google Scholar, Z. Vance J.E. M.H. Voelker Vance D.E. J. Biol. Chem. Full Text PDF PubMed Google Scholar). The of DGAT2 with mitochondria by that DGAT2 is present in We examined of cells, a cell in which S.J. Vance J.E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), that expressed DGAT2 (13Stone S.J. Myers H.M. Watkins S.M. Brown B.E. Feingold K.R. Elias P.M. Farese Jr., R.V. J. Biol. Chem. 2004; 279: 11767-11776Abstract Full Text Full Text PDF PubMed Scopus (462) Google Scholar). that DGAT2 and present in the and also enriched in that is enriched in is with a that the of in cells is present in H. G. T. Biol. 2008; PubMed Scopus Google Scholar). that DGAT2 is present in MAM, we also in and mitochondria that from from DGAT1 mice that a which that of DGAT2, was in the mitochondria in the are with Thus, of both cultured cells and murine that DGAT2 is present in The N-terminal 67 of DGAT2 to DGAT2 co-localized with mitochondria by and was present in MAM, we that it a mitochondrial targeting of a of positively amino acids a D. PubMed Scopus Google Scholar). members of the DGAT2 family, DGAT2 an N-terminal of 67 amino acids that is to the S.J. Farese Jr., R.V. J. Biol. Chem. 2006; 281: Full Text Full Text PDF PubMed Scopus Google Scholar). this of 67 amino we identified a mitochondrial targeting of positively amino acids and of murine that the of DGAT2 and are highly conserved the N terminus of DGAT2 is in mitochondrial we amino acids to the N terminus of expressed the protein in cells, and examined its subcellular a and completely co-localized with a cytosolic not with the We also examined the subcellular of in the protein was in the mitochondria in the cytosolic and In was found in the cytosolic and was not localized to mitochondria The of was by with and 3-phosphate was found in the mitochondria was in but was most in the mitochondria likely it was most in the cytosolic Thus, from both and fractionation that a mitochondrial targeting the first 67 amino acids of DGAT2. a to the the N-terminal 67 amino acids of DGAT2 that mitochondrial We examined the localization of amino acids of the N terminus a and not with In amino acids sufficient to localize to mitochondria. amino acids and are for targeting to mitochondria, we a in which these amino acids to This not with mitochondria indicating that these amino acids are for mitochondrial of the in the in of the also with DGAT2, we expressed DGAT2 in in which amino acids and in which in the putative mitochondrial targeting signal to and a highly conserved We first examined in cells these the and of in to that of DGAT2 the was with that of DGAT2 that amino acids are for the catalytic of DGAT2. The of DGAT2 to promote the formation of lipid droplets with and Next, we for these DGAT2 in of amino acids not to the mitochondrial association of DGAT2, both and DGAT2 present in mitochondria in of the putative mitochondrial targeting the of DGAT2 in the mitochondria of the protein was present in the mitochondria We also to the of DGAT2 and the and with the mitochondrial In with the fractionation the and but not the mitochondrial association and for multiple cells in the of DGAT2 to with lipid droplets was not by the was lipid association on the catalytic of these DGAT2 of mitochondria with DGAT2 and in was in The of was from and cell at was in The of was from and cell at was in The of was from and cell at in a In this we examined the subcellular of DGAT2, the major enzyme of TG in eukaryotes. and we found that DGAT2 was present in the ER and enriched in DGAT2 also with the surface of lipid droplets and co-localized with mitochondria, cells with to the and mitochondrial compartments to in a highly conserved, positively mitochondrial targeting signal that is present in the N terminus between amino acids 61 and of murine DGAT2, where it likely association of DGAT2 with mitochondria. that DGAT2 is localized to different subcellular compartments, including the ER, lipid droplets, and This localization may promote the synthesis and storage of TG in lipid droplets. enzymes to be present in the of from revealed A. Prog. Lipid Res. PubMed Scopus Google Scholar, Kennedy J. Biol. Chem. Full Text PDF PubMed Google Scholar, Z. M.H. Vance J.E. J. Biol. Chem. Full Text PDF PubMed Google Scholar, M. M. J. A. A. S. J. Lipid Res. Full Text PDF PubMed Google Scholar, R.M. J. Biol. Chem. Full Text PDF PubMed Google Scholar). In this we on the localization of DGAT2, which was present in the ER, as by both and fractionation cells to promote lipid DGAT2 lipid droplets. This localization was not found to a for DGAT1 and was not on the of the lipid droplets. DGAT2 was present near the surfaces of both and droplets, DGAT1 and not present lipid droplets of that DGAT2 localizes to lipid droplets with a of localization for of the S. of DGAT2 Kennedy J. Biol. Chem. Full Text PDF PubMed Google Scholar). DGAT2 in the was from the lipid K.D. J.T. A. Voelker T. J. Biol. Chem. 2001; 276: Full Text Full Text PDF PubMed Scopus Google Scholar). DGAT2 in cells and DGAT2 in was to with lipid droplets L. C. C. 2008; PubMed Scopus Google Scholar). that DGAT2 with ADRP, a cells of the of not between DGAT2 on the surface of lipid droplets and DGAT2 in membrane of the ER in to lipid droplets. DGAT2 a amino acids that two transmembrane domains a that is in the S.J. Farese Jr., R.V. J. Biol. Chem. 2006; 281: Full Text Full Text PDF PubMed Scopus Google Scholar). The the protein to with the lipid localization localization of DGAT2 on lipid droplets L. C. C. 2008; PubMed Scopus Google Scholar). the a with two domains it likely that DGAT2 is present in a membrane in to the The is by the of of the of lipid droplets from cells and G. L. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar, S. M. T. T. H. T. M. J. Biochem. 2006; PubMed Scopus Google Scholar, S. M. T. C. A. 2006; PubMed Scopus Google Scholar, Z. J. PubMed Scopus Google Scholar, M. D. L. G. J. H. 2006; Full Text Full Text PDF PubMed Scopus Google Scholar, S. 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Chem. 1991; 266: Full Text PDF PubMed Google Scholar, G. Vance J.E. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, J.E. J. Biol. Chem. Full Text PDF PubMed Google Scholar). that DGAT2 for at a portion of in the was the of DGAT2, but not DGAT1 with mitochondria in cells that that a portion of DGAT2 in cells with mitochondria. a DGAT2 not DGAT2 in cells such as we to DGAT2 the mitochondrial in The of DGAT2 in and the of DGAT2 with mitochondria in to DGAT2 a mitochondrial targeting We on the N-terminal of DGAT2, which a acid that is not found in family members acids to the mitochondria, where it with the mitochondrial positively amino and for the mitochondrial association of and the mitochondrial association of DGAT2. amino acids are to the of DGAT, to the of mitochondrial targeting D. PubMed Scopus Google Scholar). the of DGAT2 is a mitochondrial enzyme is present in a such MAM, which is with mitochondria. on we a in which DGAT2 is enriched in MAM, and DGAT2 in this with mitochondria as a protein via its N In this DGAT2 not be present in mitochondrial In of this have identified in the mitochondrial from and Harris R.A. S. J. M. J. PubMed Scopus Google Scholar, J. M. Stahl E. S. M. M. Full Text Full Text PDF PubMed Scopus Google Scholar, E. B. G.M. D.E. S. R.A. PubMed Scopus Google Scholar), but DGAT2 was not DGAT2 in with mitochondria is We that this may as a between the and mitochondria that the of substrates and for TG with this many enzymes of the glycerolipid (Kennedy) pathway of lipid synthesis, which is for the synthesis of both TG and are in both ER and mitochondria (1Coleman R.A. Lee D.P. Prog. Lipid Res. 2004; 43: 134-176Crossref PubMed Scopus (705) Google Scholar, R.A. T.M. Annu. Rev. PubMed Scopus Google Scholar). the of lipid droplets, mitochondria, and the ER by S. Proc. 2001; PubMed Google Scholar, R.M. S. Res. PubMed Scopus Google Scholar, 2006; PubMed Scopus Google Scholar). that these are to promote the synthesis of in this the spatial of lipid synthesis and DGAT2, the major enzyme of TG synthesis, is not localized to the it is with lipid droplets and the and mitochondrial compartments, which are important during lipid the that lipid synthesis and storage are by a of to maximize this a the N terminus of DGAT2 may promote this of this enzymatic and lipid on this complex of cell We for the P. for of a and the C. for the S. and G. for D. for and J. Vance for on the with