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: Missing protein may be key to autism

Back to psychology news Blogs list Cancer blog  


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

Missing protein may be key to autism




A missing brain protein may be one of the culprits behind autism and other brain disorders, as per scientists at MIT's Picower Institute for Learning and Memory.

The protein, called CASK, helps in the development of synapses, which neurons use to communicate with one another and which underlie our ability to learn and remember. Improperly formed synapses could lead to mental retardation, and mutations in genes encoding certain synaptic proteins are linked to autism.

In work reported in the Dec. 6 issue of Neuron, Li-Huei Tsai, Picower Professor of Neuroscience at MIT, reported that she has uncovered an enzyme that is key to the activity of CASK.



Missing protein may be key to autism

Tsai studies a kinase (kinases are enzymes that change proteins) called Cdk5. While Cdk5's best-known role is to help new neurons form and migrate to their correct positions during brain development, "emerging evidence supports an important role for Cdk5 at the synapse," she said.

To gain a better understanding of how Cdk5 promotes synapse formation, Tsai's lab looked into how Cdk5 interacts with synapse-inducing proteins like CASK. A key scaffolding protein, CASK is one of the first proteins on the scene of a developing synapse.

Scaffolding proteins such as CASK are like site managers, supporting protein-to-protein interactions to ensure that the resulting architecture is sound. Mutations in the genes responsible for Cdk5 and CASK have been found in mental retardation patients.

"We observed that Cdk5 is critical for recruiting CASK to do its job for developing synapses," Tsai said. "Without Cdk5, CASK was not in the right place at the right time, and failed to interact with essential presynaptic components. This, in turn, led to problems with calcium influx." The flow of calcium in and out of neurons affects processes central to nervous system development and plasticity--its ability to change in response to experience.

Gene mutations and/or deletions in synaptic cell surface proteins and molecules called neurexins and neuroligins have been linked to autism. The problem with CASK recruitment investigated by the Tsai laboratory creates the same result as these genetic changes.

The Picower study also provides the first molecular explanation of how Cdk5, which also may go awry in neurodegenerative diseases such as Alzheimer's, promotes synapse development.

"There are still a lot of unknowns," said Tsai, who is also a Howard Hughes Medical Institute investigator. "Causes for psychiatric disorders are still very unclear, but accumulating evidence strongly suggests that alterations in the synaptogenesis program can lead to these serious diseases".

In addition to Tsai and Picower researcher Benjamin A. Samuels, co-authors are linked to Harvard Medical School; Johns Hopkins University School of Medicine; McLean Hospital in Belmont, Mass.; and Academia Sinica in Taiwan.


Posted by: JoAnn    Source




Did you know?
A missing brain protein may be one of the culprits behind autism and other brain disorders, as per scientists at MIT's Picower Institute for Learning and Memory. The protein, called CASK, helps in the development of synapses, which neurons use to communicate with one another and which underlie our ability to learn and remember. Improperly formed synapses could lead to mental retardation, and mutations in genes encoding certain synaptic proteins are linked to autism.

Medicineworld.org: Missing protein may be key to autism

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.