title: Intestinal lipoprotein assembly.
abstract: OBJECTIVE
  The assembly of intestinal lipoproteins is critical for the transport of fat and fat-soluble vitamins. In this review we propose a nomenclature for these lipoproteins and have summarized recent data about their intracellular assembly and factors that modulate their secretion.
  
  
  RESULTS
  The assembly and secretion of intestinal lipoproteins increases with the augmented synthesis of apoB, apoAIV and lipids. Chylomicron assembly begins with the formation of primordial, phospholipid-rich particles in the membrane, and their conversion to large chylomicrons occurs in the lumen of the smooth endoplasmic reticulum. Chylomicrons are transported from the endoplasmic reticulum via specialized vesicles to the Golgi for secretion. The identification of genetic mutations in chylomicron retention disease indicates that Sar1b may play a critical role in this process. In addition to chylomicron assembly, intestinal cells have been shown to transport dietary cholesterol via apoB-independent pathways, such as efflux.
  
  
  CONCLUSIONS
  Understanding the mechanisms involved in the intracellular transport of chylomicrons and chylomicron-independent secretion pathways are expected to be the next frontiers in the field of intestinal lipoprotein assembly and secretion.
authors.affiliation: Department of Anatomy and Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, USA. mahmood.hussain@downstate.edu
authors.forename: M Mahmood
authors.initials: MM
authors.lastname: Hussain
authors.forename: Sumbul
authors.initials: S
authors.lastname: Fatma
authors.forename: Xiaoyue
authors.initials: X
authors.lastname: Pan
authors.forename: Jahangir
authors.initials: J
authors.lastname: Iqbal
mesh_terms: D001693:Biological Transport, Active; D002784:Cholesterol / Q000378:metabolism; D002914:Chylomicrons / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007422:Intestines / Q000502:physiology*; D008074:Lipoproteins / Q000096:biosynthesis* / Q000145:classification* / Q000378:metabolism; D009626:Terminology as Topic
chemical_list: D002914:Chylomicrons; D008074:Lipoproteins; D002784:Cholesterol