| Title : Comparative gene identification 58\/alpha\/beta hydrolase domain 5 lacks lysophosphatidic acid acyltransferase activity - McMahon_2014_J.Lipid.Res_55_1750 |
| Author(s) : McMahon D , Dinh A , Kurz D , Shah D , Han GS , Carman GM , Brasaemle DL |
| Ref : J Lipid Res , 55 :1750 , 2014 |
| Abstract : Mutations in the gene encoding comparative gene identification 58 (CGI-58)/alpha/beta hydrolase domain 5 (ABHD5) cause Chanarin-Dorfman syndrome, characterized by excessive triacylglycerol storage in cells and tissues. CGI-58 has been identified as a coactivator of adipose TG lipase (ATGL) and a lysophosphatidic acid acyltransferase (LPAAT). We developed a molecular model of CGI-58 structure and then mutated predicted active site residues and performed LPAAT activity assays of recombinant WT and mutated CGI-58. When mutations of predicted catalytic residues failed to reduce LPAAT activity, we determined that LPAAT activity was due to a bacterial contaminant of affinity purification procedures, plsC, the sole LPAAT in Escherichia coli. Purification protocols were optimized to reduce plsC contamination, in turn reducing LPAAT activity. When CGI-58 was expressed in SM2-1(DE3) cells that lack plsC, lysates lacked LPAAT activity. Additionally, mouse CGI-58 expressed in bacteria as a glutathione-S-transferase fusion protein and human CGI-58 expressed in yeast lacked LPAAT activity. Previously reported lipid binding activity of CGI-58 was revisited using protein-lipid overlays. Recombinant CGI-58 failed to bind lysophosphatidic acid, but interestingly, bound phosphatidylinositol 3-phosphate [PI(3)P] and phosphatidylinositol 5-phosphate [PI(5)P]. Prebinding CGI-58 with PI(3)P or PI(5)P did not alter its coactivation of ATGL in vitro. In summary, purified recombinant CGI-58 that is functional as an ATGL coactivator lacks LPAAT activity. |
| ESTHER : McMahon_2014_J.Lipid.Res_55_1750 |
| PubMedSearch : McMahon_2014_J.Lipid.Res_55_1750 |
| PubMedID: 24879803 |
| Gene_locus related to this paper: human-ABHD5 |
| Gene_locus related to this paper: human-ABHD5 |
McMahon D, Dinh A, Kurz D, Shah D, Han GS, Carman GM, Brasaemle DL (2014)
Comparative gene identification 58\/alpha\/beta hydrolase domain 5 lacks lysophosphatidic acid acyltransferase activity
J Lipid Res
55 :1750
McMahon D, Dinh A, Kurz D, Shah D, Han GS, Carman GM, Brasaemle DL (2014)
J Lipid Res
55 :1750