Navigation Links
RNA splicing occurs in nerve-cell dendrites

Researchers at the University of Pennsylvania School of Medicine have discovered that nerve-cell dendrites have the capacity to splice messenger RNA (pre-mRNA), a process once believed to only take place in the nucleus of cells.

By uncovering this capability in dendrites, the investigators hope to relate this capacity to memory and learning, as well as cognitive dysfunction. Senior author James Eberwine, PhD, Professor of Pharmacology, and lead authors Kevin Miyashiro, and Jason Glanzer, PhD, both in Eberwine's lab, report their findings in this week's early online edition of the Proceedings of the National Academy of Sciences.

Dendrites, which branch from the cell body of the neuron, play a key role in the communication between cells of the nervous system, allowing for many neurons to connect with each other to form a network. Dendrites detect the electrical and chemical signals transmitted to the neuron by the axons of other neurons. The synapse is the neuronal structure where this chemical connection is formed, and investigators surmise that the synapse is where learning and memory occur.

Researchers have long agreed that mRNA splicing takes place within the cell nucleus. In the nucleus of a mammalian cell, a gene is copied into mRNA, which possesses both exons (mature mRNA regions destined to code for proteins) and introns (non-coding regions). mRNA splicing works by cutting out introns and merging together the remaining exon pieces, resulting in an mRNA capable of being translated into a specific protein.

The vast array of proteins within the human body arises in part from the many ways that mRNAs can be spliced and reconnected. Specifically, splicing removes pieces of intron and exon regions from the RNA, with the resulting spliced RNA often being made into protein. Should the RNA have different exons spliced in and out of it, then different proteins can be made from this RNA. The Eberwine lab was successful in showing that s plicing can occur in dendrites because they have employed very sensitive technologies developed in their lab, which permits the detection and quantification of RNA splicing as well as the translated protein in single isolated dendrites.

"In addition to showing that mRNA splicing occurs in dendrites in which we added mRNA, we also detected the resulting protein," notes Eberwine. "Since the splicing machinery is present in dendrites, one could speculate that if pre-mRNA is present naturally in the dendrite, when activated, it may be spliced and translated, giving rise to many different proteins."

Protein diversity is a key aspect to the complexity of the central nervous system. Proteins are the workhorses of the cell and are generally responsible for insuring that cells function properly. When proteins interact with one another they can elicit specific physiological responses, including the generation and maintenance of memories. Changing protein identity, as can occur with splicing, can change the ability of the protein to interact with other proteins and therefore potentially change such physiological processes. With the dendrite being the initial site in the neuron where learning is thought to occur, the ability to create a diversity of mRNAs, through local splicing, and subsequent protein translation may permit exquisitely sensitive control of these cellular functions.

"The regulation and timing of the expression of proteins is what makes the central nervous system function," says Eberwine. The diversity and redundancy of the nervous-system proteins may serve to help maintain the system over a lifetime. However, failure in protein regulation or proper expression in neurons may give rise to cognitive dysfunction. "Most neurodegenerative and psychiatric illnesses exhibit dendrite dysfunction, therefore, the inability to properly generate spliced RNAs in dendrites or proteins may underlie aspects of these disease processes."

By revealing the capacity of mRNA splicing in dendrites, the investigators hope to develop an understanding of its role in cognition and dysfunction. Eberwine and colleagues are now working to find an endogenous mRNA that will undergo splicing within dendrites.

Co-authors in addition to Eberwine, Glanzer, and Miyashiro are Jai-Yoon Sul, Lindy Barrett, Brian Belt, and Phillip Haydon, all from Penn. This worked was funded by the National Institute on Aging and the National Institute on Mental Health.


'"/>

Source:University of Pennsylvania School of Medicine


Related biology news :

1. Protein splicing upsets the DNA colinearity paradigm
2. RNA map provides first comprehensive understanding of alternative splicing
3. RNA splicing factor implicated in ovarian tumor cell growth
4. OHSU study says stem cell fusion occurs in tumors
5. 3 proteins may play important role in nerve-cell repair
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/26/2016)... , April 27, 2016 ... the  "Global Multi-modal Biometrics Market 2016-2020"  report to ... ) , The analysts forecast the ... CAGR of 15.49% during the period 2016-2020.  ... number of sectors such as the healthcare, BFSI, ...
(Date:4/15/2016)... April 15, 2016  A new partnership announced ... accurate underwriting decisions in a fraction of the ... priced and high-value life insurance policies to consumers ... With Force Diagnostics, rapid testing (A1C, Cotinine ... readings (blood pressure, weight, pulse, BMI, and activity ...
(Date:4/14/2016)... , April 14, 2016 ... Malware Detection, today announced the appointment of Eyal ... new role. Goldwerger,s leadership appointment comes at ... heels of the deployment of its platform at several ... biometric technology, which discerns unique cognitive and physiological factors, ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... NEW YORK , June, 23, 2016  The ... students to envision new ways to harness living systems ... of Modern Art (MoMA) in New York ... more than 130 participating students, showcased projects at MoMA,s ... included Paola Antonelli , MoMA,s senior curator of ...
(Date:6/23/2016)... Apellis Pharmaceuticals, Inc. today announced positive ... its complement C3 inhibitor, APL-2. The trials were ... studies designed to assess the safety, tolerability, pharmacokinetics ... healthy adult volunteers. Forty subjects were ... dose (ranging from 45 to 1,440mg) or repeated ...
(Date:6/23/2016)... ... June 23, 2016 , ... Regulatory ... technical consulting, provides a free webinar on Performing Quality Investigations: Getting ... at 12pm CT at no charge. , Incomplete investigations are still a major ...
(Date:6/22/2016)... 22, 2016 Research and Markets has announced ... report to their offering. ... from $29.3 billion in 2013. The market is expected to grow ... 2015 to 2020, increasing from $50.6 billion in 2015 to $96.6 ... during the forecast period (2015 to 2020) are discussed. As well, ...
Breaking Biology Technology: