In postmortem human brain samples and in Drosophila models of tauopathy, significant changes in the pattern of transposable element (TE) transcription are observed, relative to healthy samples. Expression of either mutant or wild-type human tau (Hsap\MAPT) in the fly brain is sufficient to activate numerous TEs. Heterochromatin decondensation is observed; piwi protein is depleted; specific classes of piRNAs are depleted. Genetic manipulations that interfere with piRNAs increase both TE expression and tau-induced neurotoxicity; overexpression of piwi has the opposite effects.
Somatic mutations of the human PIN1 gene have been observed in postmortem brain samples of Alzheimer disease patients. The fly ortholog of PIN1 is dod. In the fly Hsap\MAPT tauopathy model, levels of the fly gene dod are strongly reduced in the fly brain. Restoration of dod levels suppresses the Hsap\MAPT-dependent phenotypes, including heterochromatin changes, TE upregulation, neurodegeneration, and fly motor defects.
See also the human disease model report 'tauopathies, MAPT-related' (FBhh0000101).
[updated Oct. 2021 by FlyBase; FBrf0222196]
PIN1 encodes a peptidyl-prolyl cis/trans isomerase (PPIase) that specifically binds to phosphorylated ser/thr-pro motifs to catalytically regulate the post-phosphorylation conformation of its substrates. [Gene Cards, PIN1; 2021.10.16]
Many to one: 3 human to 1 Drosophila. Three human genes, MAPT, MAP2 and MAP4, are orthologous to the fly gene Dmel\tau.