title: Is there a role of the cyclin-dependent kinase 5 activator p25 in Alzheimer's disease?
abstract: Sporadic Alzheimer's disease is the leading cause of dementia, but the underlying molecular processes are still unknown. Several studies have observed an accumulation of the protein fragment p25 in sporadic Alzheimer's disease brain. p25 derives from proteolysis of p35, and overactivates the tau kinase cyclin-dependent kinase 5. Transgenic mice expressing high levels of p25 exhibit hyperphosphorylation of tau as seen in Alzheimer's disease, and neurodegeneration. In contrast, low-level p25 expression, less than half of endogenous p35 expression, has a sex-specific effect on hippocampal synaptic plasticity and improves spatial learning in female but not in male mice. Therefore, p25 formation may initially be a compensatory response for early learning deficits in Alzheimer's disease, but continued formation could contribute to detrimental changes in Alzheimer's disease.
authors.affiliation: Wolfson Institute for Biomedical Research, University College London, London, UK. p.giese@ucl.ac.uk
authors.forename: K Peter
authors.initials: KP
authors.lastname: Giese
authors.forename: Laurence
authors.initials: L
authors.lastname: Ris
authors.forename: Florian
authors.initials: F
authors.lastname: Plattner
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000503:physiopathology; D000818:Animals; D051360:Cyclin-Dependent Kinase 5 / Q000378:metabolism*; D004195:Disease Models, Animal; D020536:Enzyme Activators / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000502:physiology*; D019636:Neurodegenerative Diseases / Q000235:genetics / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology
chemical_list: D020536:Enzyme Activators; D009419:Nerve Tissue Proteins; C118136:TPPP protein, human; D051360:Cyclin-Dependent Kinase 5