Biomaterial Database

Alzheimer paired helical filaments. Restoration of the biological activity by dephosphorylation. 1994

K Iqbal, and T Zaidi, and C Bancher, and I Grundke-Iqbal

New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314.

In a normal mature neuron, microtubule associated protein tau promotes the assembly of tubulin into microtubules and maintains the structure of microtubules. In Alzheimer disease brain, tau is abnormally hyperphosphorylated and is the major protein subunit of paired helical filaments (PHF). In the present study, the biological activity of tau in PHF and the effect of dephosphorylation on this activity were examined. PHF were isolated from Alzheimer disease brains and tau from the untreated or alkaline phosphatase-treated PHF was extracted by ultrasonication in microtubule assembly buffer. Tubulin was isolated by phosphocellulose chromatography of three cycled microtubules from bovine brain. PHF-tau did not promote assembly of bovine tubulin into microtubules whereas tau from the dephosphorylated PHF produced a robust microtubule assembly. These studies suggest (i) that in Alzheimer disease tau in PHF is functionally inactive because of abnormal phosphorylation and (ii) that the abnormally phosphorylated site(s) in PHF that inactivates PHF-tau is accessible to enzymatic dephosphorylation in vitro.

UI	MeSH Term	Description	Entries
D008870	Microtubules	Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.	Microtubule
D010750	Phosphoproteins		Phosphoprotein
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000469	Alkaline Phosphatase	An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
D000544	Alzheimer Disease	A degenerative disease of the BRAIN characterized by the insidious onset of DEMENTIA. Impairment of MEMORY, judgment, attention span, and problem solving skills are followed by severe APRAXIAS and a global loss of cognitive abilities. The condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of SENILE PLAQUES; NEUROFIBRILLARY TANGLES; and NEUROPIL THREADS. (From Adams et al., Principles of Neurology, 6th ed, pp1049-57)	Acute Confusional Senile Dementia,Alzheimer's Diseases,Dementia, Alzheimer Type,Dementia, Senile,Presenile Alzheimer Dementia,Senile Dementia, Alzheimer Type,Alzheimer Dementia,Alzheimer Disease, Early Onset,Alzheimer Disease, Late Onset,Alzheimer Sclerosis,Alzheimer Syndrome,Alzheimer Type Senile Dementia,Alzheimer's Disease,Alzheimer's Disease, Focal Onset,Alzheimer-Type Dementia (ATD),Dementia, Presenile,Dementia, Primary Senile Degenerative,Early Onset Alzheimer Disease,Familial Alzheimer Disease (FAD),Focal Onset Alzheimer's Disease,Late Onset Alzheimer Disease,Primary Senile Degenerative Dementia,Senile Dementia, Acute Confusional,Alzheimer Dementias,Alzheimer Disease, Familial (FAD),Alzheimer Diseases,Alzheimer Type Dementia,Alzheimer Type Dementia (ATD),Alzheimers Diseases,Dementia, Alzheimer,Dementia, Alzheimer-Type (ATD),Familial Alzheimer Diseases (FAD),Presenile Dementia,Sclerosis, Alzheimer,Senile Dementia
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014404	Tubulin	A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.	alpha-Tubulin,beta-Tubulin,delta-Tubulin,epsilon-Tubulin,gamma-Tubulin,alpha Tubulin,beta Tubulin,delta Tubulin,epsilon Tubulin,gamma Tubulin