We studied the changes occurring in the membrane environment of prion protein (PrP) during apoptosis induced by low potassium in primary rat cerebellar neurons. Ceramide levels increased during apoptosis-inducing treatment, being doubled with respect to time-matched controls after 24 h. Sphingomyelin levels were parallely decreased, while cholesterol and ganglioside contents were not affected. Changes in ceramide and sphingomyelin composition were exclusively restricted to a detergent-resistant membrane fraction. The pro-apoptotic treatment was accompanied by the down-regulation of PrP and of the non-receptor kinase Fyn. The levels of PrP and Fyn were correspondingly reduced in the detergent-resistant membrane fraction. In control cells, the membrane microenvironment separated by immunoprecipitation with anti-PrP antibody contained 80% of the detergent-resistant PrP and 35% and 38% of the sphingolipids and cholesterol respectively. Upon low potassium treatment, 20% of the PrP originally present in the detergent-resistant fraction was immunoprecipitated, together with 19% of sphingolipids and 22% of cholesterol. Thus, PrP in the immunoprecipitate from apoptotic cells was ninefold less than in control ones, while sphingolipids and cholesterol were about 50% with respect to controls cells. The molar ratio between cholesterol, sphingomyelin and ceramide was 15:6:1 in the PrP-rich environment from control neurons, and 6:2:1 in that from apoptotic cells.
Reorganization of prion protein membrane environment during low-potassium induced apoptosis in primary rat cerebellar neurons / A. Rivaroli, S. Prioni, N. Loberto, A. Bettiga, V. Chigorno, A. Prinetti, S. Sonnino. - In: JOURNAL OF NEUROCHEMISTRY. - ISSN 0022-3042. - 103:5(2007), pp. 1954-1967.
|Titolo:||Reorganization of prion protein membrane environment during low-potassium induced apoptosis in primary rat cerebellar neurons|
RIVAROLI, ANNA (Primo)
PRIONI, SIMONA (Secondo)
PRINETTI, ALESSANDRO ENNIO GIUSEPPE (Penultimo)
SONNINO, SANDRO (Ultimo)
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
Settore BIO/12 - Biochimica Clinica e Biologia Molecolare Clinica
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1111/j.1471-4159.2007.04890.x|
|Appare nelle tipologie:||01 - Articolo su periodico|