出版社：American Society for Biochemistry and Molecular Biology
摘要：Angiopoietin-like protein 3 and 4 (Angptl3 and Angptl4) aretwo members of the angiopoietin-like family of proteins. Thesetwo closely related proteins have been reported to similarlyaffect lipid metabolism through their capacity to inhibit lipoproteinlipase. We undertook a series of studies to compare the structure,function, and regulation of Angptl3 and Angptl4. Previously,we reported that Angptl4 exists as variable-sized oligomersthat contain intermolecular disulfide bonds. We now have evidencethat although there are no intermolecular disulfide bonds evidentin Angptl3, higher molecular weight forms do exist. In addition,Angptl4 exhibits a widespread distribution of tissue expression,while Angptl3 is exclusively expressed in the liver. Treatmentswith various ligands of nuclear receptors reveal that Angptl3is a target gene of liver X receptor, while Angptl4 expressionis activated by ligands of all peroxisome proliferator-activatedreceptors. Expression of Angptl4 in adipose tissue and liveris induced by fasting, while Angptl3 expression is not appreciablyaffected by nutritional status.
We suggest that the differential regulation of Angptl3 and Angptl4by sites of expression, nutritional status, and ligands of nuclearreceptors may confer unique roles of each in lipoprotein metabolism.Supplementary key words Angptl3 • Angptl4 • LPL • peroxisome proliferator-activated receptor • liver X receptor • gel filtration • nutritional status
