Philip MacArthur
Matriculation Year: 2006
Department: Pathology - Lipid Sciences
Education:
- BA (1999) Anthropology. University of Georgia, Athens, GA.
Research Summary:
Microsomal triglyceride transfer protein (MTP) is an essential cofactor for the formation of apolipoprotein B (apoB)-containing lipoproteins including, hepatic very low density lipoproteins (VLDL) and intestinal chylomicrons. MTP is a multifunctional protein necessary for both conversion of apoB into precursor lipoproteins (first-step assembly) and bulk neutral lipid movement into the endoplasmic reticulum (ER) for precursor lipoprotein particle expansion (second-step assembly). Previous results have established that invertebrate forms of MTP (e.g., Drosophila melanogaster) are capable of phospholipid (PL) transfer whereas vertebrate forms of MTP (e.g., human) engage in both in PL and triglyceride (TG) transfer. Hence, it is possible that PL transfer is the primordial function of MTP necessary for precursor lipoprotein particle formation, a process akin to formation of primitive lipoproteins in invertebrate species, whereas TG transfer by MTP may be an evolutionary adaptation that enables the trafficking of neutral lipids into the ER for second-step particle expansion, a process unique to vertebrate lipoprotein producing cells. The overall goals of my research are to determine 1) whether MTP is the sole tissue specific factor necessary and sufficient to achieve neutral lipid translocation into the ER and 2) whether the different lipid transfer activities of MTP, specifically PL and TG transfer, play distinct and separable roles in lipoprotein formation.
Publications: