ApoE is Secreted as a Lipid Nanoparticle by Mammalian Cells: Implications for Alzheimer's Disease Pathogenesis.

ABSTRACT: The brain is the most cholesterol-rich organ in the body, and ApoE is the main lipid carrier protein in the brain. Although very little, if any, ApoE exists in its apoprotein form in physiological fluids, recombinant ApoE is typically prepared in a lipid-free state to study its physiological functions. We describe a lipid nanoparticle (LNP) form of ApoE as a primary extracellular product of the eukaryotic protein export system. Whereas the apoprotein is the dominant secreted product when the APOE gene is overexpressed in mammalian cells, an LNP form of ApoE is also observed. The LNP form is, however, the major secreted product from unmodified CCF-STTG1 astrocytoma cells. The C-terminal domain of ApoE plays a key role in LNP biosynthesis as the ApoE3 W210* truncation mutant is secret

SUBMITTER: Hernandez Arriaza R 

PROVIDER: S-EPMC12616577 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature