Planar cell polarity (PCP) describes a cell-cell communication process through which individual cells coordinate and align within the plane of a tissue. In this study， we show that overexpression of ， a PCP gene， triggers neuronal apoptosis via the dishevelled/Rac1 GTPase/MEKK1/JNK/caspase signalling axis. Consistent with this finding， endogenous expression is upregulated in models of polyglutamine (polyQ) diseases and in fibroblasts from spinocerebellar ataxia type 3 (SCA3) patients. The disruption of this upregulation mitigates polyQ-induced neurodegeneration in We show that the transcriptional regulator Yin Yang 1 (YY1) associates with the promoter. Overexpression of YY1 promotes the hypermethylation of promoter， causing transcriptional repression of Remarkably， YY1 protein is recruited to ATXN3-Q84 aggregates， which reduces the level of functional， soluble YY1， resulting in transcriptional derepression and induction of neuronal apoptosis. Furthermore， transcript level is elevated in amyloid beta-peptide， Tau and α-synuclein models， implicating its potential involvement in other neurodegenerative diseases， such as Alzheimer's and Parkinson's diseases. Taken together， this study unveils a generic Fuz-mediated apoptotic cell death pathway in neurodegenerative disorders.