Deficiency of the INCL protein Ppt1 results in changes in ectopic F1-ATP synthase and altered cholesterol metabolism.
Hum Mol Genet
; 17(10): 1406-17, 2008 May 15.
Article
em En
| MEDLINE
| ID: mdl-18245779
ABSTRACT
Infantile neuronal ceroid lipofuscinosis (INCL) is a severe neurodegenerative disease caused by deficiency of palmitoyl protein thioesterase 1 (PPT1). INCL results in dramatic loss of thalamocortical neurons, but the disease mechanism has remained elusive. In the present work we describe the first interaction partner of PPT1, the F(1)-complex of the mitochondrial ATP synthase, by co-purification and in vitro-binding assays. In addition to mitochondria, subunits of F(1)-complex have been reported to localize in the plasma membrane, and to be capable of acting as receptors for various ligands such as apolipoprotein A-1. We verified here the plasma membrane localization of F(1)-subunits on mouse primary neurons and fibroblasts by cell surface biotinylation and TIRF-microscopy. To gain further insight into the Ppt1-mediated properties of the F(1)-complex, we utilized the Ppt1-deficient Ppt1(Delta ex4) mice. While no changes in the mitochondrial function could be detected in the brain of the Ppt1(Delta ex4) mice, the levels of F(1)-subunits alpha and beta on the plasma membrane were specifically increased in the Ppt1(Delta ex4) neurons. Significant changes were also detected in the apolipoprotein A-I uptake by the Ppt1(Delta ex4) neurons and the serum lipid composition in the Ppt1(Delta ex4) mice. These data indicate neuron-specific changes for F(1)-complex in the Ppt1-deficient cells and give clues for a possible link between lipid metabolism and neurodegeneration in INCL.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Limite:
Animals
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article