Apolipoprotein A-I induces translocation of protein kinase C[alpha] to a cytosolic lipid-protein particle in astrocytes.
J Lipid Res
; 45(12): 2269-76, 2004 Dec.
Article
in En
| MEDLINE
| ID: mdl-15375180
ABSTRACT
Apolipoprotein A-I (apoA-I) induces the translocation of newly synthesized cholesterol as well as caveolin-1 to the cytosolic lipid-protein particle (CLPP) fraction in astrocytes before its appearance in high density lipoprotein generated in the medium (Ito, J., Y. Nagayasu, K. Kato, R. Sato, and S. Yokoyama. 2002. Apolipoprotein A-I induces translocation of cholesterol, phospholipid, and caveolin-1 to cytosol in rat astrocytes. J. Biol. Chem. 277 7929-7935). We here report the association of signal-related molecules with CLPP. ApoA-I induces rapid translocation of protein kinase Calpha to the CLPP fraction and its phosphorylation in astrocytes. ApoA-I also induces the translocation of phospholipase Cgamma to CLPP. Diacylglyceride (DG) production is increased by apoA-I in the cells, with a maximum at 5 min after the stimulation, and the increase takes place also in the CLPP fraction. An inhibitor of receptor-coupled phospholipase C, U73122, inhibited all the apoA-I-induced events, such as DG production, cholesterol translocation to the cytosol, release of cholesterol, and translocation of protein kinase Calpha into the CLPP fraction. CLPP may thus be involved in the apoA-I-initiated signal transduction in astrocytes that is related to intracellular cholesterol trafficking for the generation of high density lipoprotein in the brain.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Kinase C
/
Astrocytes
/
Apolipoprotein A-I
/
Cytosol
Limits:
Animals
Language:
En
Journal:
J Lipid Res
Year:
2004
Document type:
Article
Affiliation country:
Japan