MedicineWorld.Org
Your gateway to the world of medicine
Home
News
Cancer News
About Us
Cancer
Health Professionals
Patients and public
Contact Us
Disclaimer

Medicineworld.org: How neuronal activity leads to Alzheimer's protein cleavage

Back to neurology news Blogs list Cancer blog  


Subscribe To Neurology News RSS Feed  RSS content feed What is RSS feed?

How neuronal activity leads to Alzheimer's protein cleavage




Amyloid precursor protein (APP), whose cleavage product, amyloid-b (Ab), builds up into fibrous plaques in the brains of Alzheimer's disease patients, jumps from one specialized membrane microdomain to another to be cleaved, report Sakurai et al.

Eventhough there is no definitive evidence that Ab plaques are the direct cause of Alzheimer's disease, there is much circumstantial evidence to support this. And working on this hypothesis, researchers are investigating just how the plaques form and what might be done to stop or reverse their formation.



How neuronal activity leads to Alzheimer's protein cleavage

APP, a protein of unknown function, is membrane associated and concentrates at the neuronal synapse. Certain factors such as high cellular cholesterol and increased neuronal or synaptic activity are known to drive APP cleavage, and Sakurai and his colleagues' paper pulls these two modes of Ab regulation together.

APP associates with membrane microdomains high in cholesterols (lipid rafts). These lipid rafts can also contain the enzyme necessary for APP cleavage, BACE. Synaptic activity is known to involve a very different type of membrane microdomain high in an excytosis-promoting factor called syntaxin. Sakurai et al. now show that eventhough APP preferentially associates with syntaxin microdomains, upon neuronal stimulation APP instead associates with microdomains that contain BACE.

It's unclear why APP should be linked to syntaxin, though it might suggest a role for APP in vesicle trafficking and exocytosis. Also unclear is why neuronal activity should cause APP to jump from syntaxin domains to BACE domains. What is clear, however, is that the process is an active one, requiring a kinase called cdk5. Furthermore, treating neurons with a cdk5 inhibitor called roscovitine, which is currently in trials for cancer therapy, reduced APP's association with BACE microdomains and reduced APP cleavage.


Posted by: Daniel    Source




Did you know?
Amyloid precursor protein (APP), whose cleavage product, amyloid-b (Ab), builds up into fibrous plaques in the brains of Alzheimer's disease patients, jumps from one specialized membrane microdomain to another to be cleaved, report Sakurai et al. Eventhough there is no definitive evidence that Ab plaques are the direct cause of Alzheimer's disease, there is much circumstantial evidence to support this. And working on this hypothesis, researchers are investigating just how the plaques form and what might be done to stop or reverse their formation.

Medicineworld.org: How neuronal activity leads to Alzheimer's protein cleavage

Acute bacterial meningitis| Alzheimer's disease| Carpal tunnel syndrome| Cerebral aneurysms| Cerebral palsy| Chronic fatigue syndrome| Cluster headache| Dementia| Epilepsy seizure disorders| Febrile seizures| Guillain barre syndrome| Head injury| Hydrocephalus| Neurology| Insomnia| Low backache| Mental retardation| Migraine headaches| Multiple sclerosis| Myasthenia gravis| Neurological manifestations of aids| Parkinsonism parkinson's disease| Personality disorders| Sleep disorders insomnia| Syncope| Trigeminal neuralgia| Vertigo|

Copyright statement
The contents of this web page are protected. Legal action may follow for reproduction of materials without permission.