Intracellular trafficking lysosomal proteins

The trafficking of lipoprotein-derived cholesterol from lysosomes has been a major area of focus in the field of intracellular cholesterol metabolism, and many of the cellular and molecular events are not known (Chapter 17). By analyzing cells with mutations in cholesterol transport, investigators have identified roles for two proteins, called NPCl and NPC2 (HEl), in lysosomal and/or endosomal cholesterol transport (E.J. Blanchette-Mackie, 2000 P. Lobel, 2000). In addition, the lipid lysobisphosphatidic acid and certain GTPases called Rab proteins may also play roles in these processes (J. Gruenberg, 1999 E. Ikonen, 2006). The mechanisms by which these molecules are involved in cholesterol transport, however, are poorly understood [14]. 

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