Navigation Links
Scientists link fragile X tremor/ataxia syndrome to binding protein in RNA
Date:8/15/2007

Scientists have discovered a key protein in the toxic brain pathway that leads to fragile X tremor/ataxia syndrome (FXTAS), an inherited neurodegenerative disorder. The finding, in a Drosophila (fly) model of FXTAS, could help unravel the complex mechanisms of FXTAS and lead scientists to develop therapies to target the protein. The research will be published in the Aug. 16 issue of the journal Neuron.

Fragile X tremor/ataxia syndrome was first recognized several years ago as a neurodegenerative disease caused by a premutation in carriers of the mutated FMR1 gene, the same gene that causes fragile X syndrome--the most common inherited cause of mental retardation. Individuals with the FMR1 premutation (a less exaggerated form of the mutation) do not have retardation, but instead are at risk for developing FXTAS, usually after age 50, causing progressive problems with movement (ataxia), tremor, memory loss, loss of sensation in the lower extremities (peripheral neuropathy), and mental and behavioral changes.

Fragile X syndrome occurs when a region of the FMR1 gene repeats a particular sequence of three DNA basesCGG--causing silencing of the FMRP protein. Called a trinucleotide repeat, this CGG sequence repeats only about 6 to 55 times in normal individuals, but between 200 and 1,000 times in those with fragile X syndrome.

In those with the premutation of the FMR1 gene, CGG repeats between 60 and 100 times.

Scientists estimate the frequency of fragile X syndrome as approximately 1 in 4,000 males and 1 in 8,000 females and the frequency of the FMR1 premutation as 1 in 800 males and 1 in 260 females. Approximately 20 percent of males with the permutation develop FXTAS. Approximately 20 percent of women with the premutation have premature ovarian failure a loss of ovarian function in women younger than 40.

Lead authors of the current study are Peng Jin, PhD, assistant professor of human genetics and Stephen T. Warren, PhD, Timmie professor and chair of human genetics at Emory University School of Medicine. Dr. Warren and his colleagues led an international team that discovered the FMR1 gene in 1991, later characterized the FMRP protein, and developed diagnostic tests for fragile X syndrome.

Drs. Jin and Warren earlier discovered (Neuron, 2003) that FXTAS is caused by elongated repeats of the CGG sequence in cells' RNA the molecules that translate the genetic code from DNA into proteins. In the current Neuron paper, Dr. Jin describes his discovery that the pur alpha protein, which is necessary for neuronal function and is involved in brain synapses tied to movement, is bound by the CGG trinucleotide repeats located in the RNA of the FMR1 gene.

Drs. Jin and Warren believe that because the repeated CGG sequences bind and sequester the pur alpha protein, the protein is not available for its normal function in the parts of the brain responsible for movement. The researchers also found that the pur alpha protein bound to CGG repeats becomes part of toxic brain aggregates, called inclusions, found in patients with neurodegeneration.

"Now that we have discovered a protein that is depleted by RNA in the premutation gene, we will try to identify more specifically how depletion of this protein can cause neurodegeneration, and we can use our fly model to conduct drug screening and begin to develop therapeutic drugs that could overcome this problem," says Dr. Jin.


'/>"/>

Contact: Holly Korschun
hkorsch@emory.edu
404-727-3990
Emory University
Source:Eurekalert

Related biology news :

1. Wisconsin scientists grow critical nerve cells
2. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
3. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
4. UAB scientists discover the origin of a mysterious physical force
5. Fox Chase Cancer Center scientists identify immune-system mutation
6. Scientists Replicate Hepatitis C Virus in Laboratory
7. Scientists detect probable genetic cause of some Parkinsons disease cases
8. Scientists find missing enzyme for tuberculosis iron scavenging pathway
9. Scientists seek answers on what activates deadly anthrax spores
10. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
11. Scientists collaborate to assess health of global environment
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/21/2016)... Columbia , June 21, 2016 ... to the new role of principal product architect ... named the director of customer development. Both will ... chief technical officer. The moves reflect NuData,s strategic ... in response to high customer demand and customer ...
(Date:6/16/2016)... 2016 The global ... reach USD 1.83 billion by 2024, according to ... Technological proliferation and increasing demand in commercial buildings, ... drive the market growth.      (Logo: ... development of advanced multimodal techniques for biometric authentication ...
(Date:6/9/2016)... leader in attendance control systems is proud to announce the introduction of fingerprint attendance ... the right employees are actually signing in, and to even control the opening of ... ... ... Photo - ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... ... December 08, 2016 , ... ... control cells — optogenetics — is key to exciting advances in the study ... spatially patterned light projected via free-space optics stimulates small, transparent organisms and excites ...
(Date:12/8/2016)... , Dec. 8, 2016  Anaconda BioMed S.L., a ... of the next generation neuro-thrombectomy system for the treatment ... Tudor G. Jovin, MD to join its Scientific Advisory ... a strategic network of scientific and clinical experts to ... of the ANCD BRAIN ® to its clinical ...
(Date:12/8/2016)... Iowa (PRWEB) , ... December 08, 2016 , ... This ... asynchronous approvals for biotech crops. The authors focus on the economic effects in countries ... global approval of new biotech crops and the resultant risk of low level presence ...
(Date:12/8/2016)... Savannah River Remediation LLC group evaluated ... NT-MAX Lake & Pond Sludge and Muck ... conjunction with Hexa Armor/ Rhombo cover manufactured by ... Discharge Elimination System requirements. The Savannah ... of elevated pH levels, above 8.5, especially during ...
Breaking Biology Technology: