Catalyzes the transport of triglyceride between phospholipid surfaces (PubMed:17924655). Catalyzes the transport of cholesteryl ester, and phospholipid between phospholipid surfaces (By similarity). Required for the assembly and secretion of plasma lipoproteins that contain apolipoprotein B (PubMed:22581286, PubMed:17924655). Required for yolk lipid utilization and absorption of dietary lipids in larvae (PubMed:17176039). a 1,2-diacyl-sn-glycero-3-phosphocholine(in) = a 1,2-diacyl-sn-glycero-3-phosphocholine(out) a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(in) = a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(out) a cholesterol ester(in) = a cholesterol ester(out) a triacyl-sn-glycerol(in) = a triacyl-sn-glycerol(out) Inhibited by naringenin. Heterodimer; heterodimerizes with the protein disulfide isomerase. Colocalizes with P4HB/PDI in the endoplasmic reticulum. Highest expression in the proximal part of the anterior intestine. Lower expression in the distal part of the anterior intestine, in the posterior portion of the intestinal tube and liver. Very low expression levels in heart, brain, ovary, testis and kidney. Detected in the blastoderm margin by 4 hours post-fertilization (hpf). Expressed in the yolk syncytial layer (YSL) from 9 hpf to 24 hpf. By 48 hpf expression decreases in the extraembryonic YSL and is detected in the embryonic liver primordium and intestinal tube in which strongly expressed by 4 days post-fertilization (dpf). At 6 and 15 dpf expression is restricted to the two main liver lobes and the anterior part of the intestine including the intestinal bulb, but not detected in the pharynx or posterior intestine. Expressed in the enterocytes of the anterior part of intestine as well as in the hepatic cells in 15 dpf larvae. The total level of expression is very small before 2 hpf, increasing significantly between 2 and 5 hpf, and remaining high at 6 and 9 hpf. A significant decrease in the expression level is detected at 12 hpf and low level remains until the end of embryogenesis, which occurs by 72 hpf. Expression is strongly up-regulated in the anterior intestine and to a lesser extent in liver in response to feeding in both larvae and adults (at protein level) (PubMed:15614773). Protein levels are not changed in 1 or 6 hours after feeding (PubMed:17176039). Larvae do not absorb dietary neutral lipids, consume very little yolk, are small and die by 6 days post-fertilization (dpf) with pronounced edema. No defects in intestinal absorption of short chain fatty acids. Loss of visualization of neutral lipids in the vasculature, heart and head structures by oil red o staining. Levels of apolipoprotein B, vitellogenin and lipovitellin unchanged. No cardiovascular defects or global intestinal function impairment. Increased expression of Foza2 and Pgc1 proteins (PubMed:17176039). Leads to excess angiogenesis and yolk absorption defects. Decreased mRNA levels of flt1 at 24 hours post-fertilization (hpf) with no change in the mRNA levels of kdrl or flt4 or in other vascular genes (PubMed:22581286).