| First Author | Eichmann TO | Year | 2012 |
| Journal | J Biol Chem | Volume | 287 |
| Issue | 49 | Pages | 41446-57 |
| PubMed ID | 23066022 | Mgi Jnum | J:192630 |
| Mgi Id | MGI:5465510 | Doi | 10.1074/jbc.M112.400416 |
| Citation | Eichmann TO, et al. (2012) Studies on the substrate and stereo/regioselectivity of adipose triglyceride lipase, hormone-sensitive lipase, and diacylglycerol-O-acyltransferases. J Biol Chem 287(49):41446-57 |
| abstractText | Adipose triglyceride lipase (ATGL) is rate-limiting for the initial step of triacylglycerol (TAG) hydrolysis, generating diacylglycerol (DAG) and fatty acids. DAG exists in three stereochemical isoforms. Here we show that ATGL exhibits a strong preference for the hydrolysis of long-chain fatty acid esters at the sn-2 position of the glycerol backbone. The selectivity of ATGL broadens to the sn-1 position upon stimulation of the enzyme by its co-activator CGI-58. sn-1,3 DAG is the preferred substrate for the consecutive hydrolysis by hormone-sensitive lipase. Interestingly, diacylglycerol-O-acyltransferase 2, present at the endoplasmic reticulum and on lipid droplets, preferentially esterifies sn-1,3 DAG. This suggests that ATGL and diacylglycerol-O-acyltransferase 2 act coordinately in the hydrolysis/re-esterification cycle of TAGs on lipid droplets. Because ATGL preferentially generates sn-1,3 and sn-2,3, it suggests that TAG-derived DAG cannot directly enter phospholipid synthesis or activate protein kinase C without prior isomerization. |
