Identification of a mutant-like conformation of p53 in fibroblasts from sporadic Alzheimer's disease patients.
Here we show that fibroblasts from sporadic Alzheimer's disease (AD) patients specifically express an anomalous and detectable conformational state of p53 that makes these cells distinct from fibroblasts of age-matched non-AD subjects. In particular, we found that, in contrast to non-AD fibroblasts, p53 in AD fibroblasts is expressed at higher levels in resting condition, and presents a significant impairment of its DNA binding and transcriptional activity. All together, these findings figured out the presence of a mutant-like p53 phenotype. However, gene sequencing of the entire p53 gene from either AD or non-AD did not unravel point mutations. Based on immunoprecipitation studies with conformation-specific p53 antibodies (PAb1620 and PAb240), which discriminated folded versus unfolded p53 tertiary structure, we found that a significant amount of p53 assumed an unfolded tertiary structure in fibroblasts from AD patients. This conformational mutant-like p53 form was virtually undetectable in fibroblasts from non-AD patients. These data, independently from their relevance in understanding the etiopathogenesis of AD, might be useful for supporting AD diagnosis.
Uberti
Daniela
D
Department of Biomedical Sciences and Biotechnologies, University of Brescia, Viale Europa 11, 25124 Brescia, Italy. uberti@med.unibs.it
Lanni
Cristina
C
Carsana
Teresina
T
Francisconi
Simona
S
Missale
Cristina
C
Racchi
Marco
M
Govoni
Stefano
S
Memo
Maurizio
M
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000235:genetics* / Q000473:pathology*; D015153:Blotting, Western / Q000379:methods; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology; D004252:DNA Mutational Analysis / Q000379:methods; D004317:Doxorubicin / Q000494:pharmacology; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047468:Immunoprecipitation / Q000379:methods; D008297:Male; D009154:Mutation; D011487:Protein Conformation; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012867:Skin / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin; D006861:Hydrogen Peroxide; D002945:Cisplatin