Navigation Links
Structure of sodium channels different than previously believed
Date:4/17/2014

Sodium channels are implicated in many serious conditions such as heart disease, epilepsy and pain, making them an important potential target for drug therapies. Unfortunately, there is still much scientists do not know about the molecules. New Cambridge research provides fresh and unexpected insight into the structure of sodium channels and, specifically, one of its components - β-subunit molecules - which are responsible for 'fine-tuning' the activity of the channel. The research is published in the most recent edition of the Journal of Biological Chemistry.

Nerves and other electrically-excitable cells communicate with one another by transmitting electrical signals, and sodium channels play a vital role in this process. The sodium channel lies on the surface of the nerve and muscle cells and is composed of a large molecule called the α-subunit, together with smaller β-subunit molecules. The -subunits 'fine-tune' the activity of the channel, so that the initiation, frequency and duration of the action potential can be appropriately regulated. There are ten different forms of α-subunits and four different forms of -subunits. These are expressed in different types of cells and organs within the body.

The new Cambridge research was carried out by Sivakumar Namadurai and led by Dr Tony Jackson and Dr Dima Chirgadze from the University of Cambridge's Department of Biochemistry, and focussed on one of the -subunits, called β3. This molecule is particularly important in regulating sodium channels located on heart cells.

For the study, the researchers used a technique called protein X-ray crystallography to determine the atomic-resolution structure of a part of the 3-subunit called the 'immunoglobulin domain'. This region of the 3-subunit lies on the outside of the cell and binds to the heart sodium channel α-subunit.

They discovered that three 3-immunoglobulin domains come together to form a trimer (so-called because it is made up of three molecules). Using a technique called atomic force microscopy, Dilshan Balasuriya, led by Professor Mike Edwardson in Cambridge's Department of Pharmacology, imaged individual 3 trimers and confirmed that the complete 3-subunit trimers cross-linked up to three sodium channel α-subunits.

"Our results were unexpected," said Dr Jackson. "We have been working on the 3-subunit for about 14 years. In all that time, we have had to infer events at the molecular level indirectly. To actually see the atomic structure of the subunit and how it forms the trimer was one of those rare 'a-ha!' moments, like switching on a light bulb."

Dr Chirgadze added: "Our research has important implications for our understanding of the mechanism of sodium channel behaviour. Up until now there has been an assumption that individual sodium channels function independently. But this might be too simple a view. One very exciting possibility is that the cross-linking of sodium channel α-subunits by 3 trimers could lead to several sodium channels being functionally connected together. If correct, this would allow a more efficient initiation of the action potential."


'/>"/>

Contact: Communications Office
communications@admin.cam.ac.uk
44-012-233-32300
University of Cambridge
Source:Eurekalert

Related biology news :

1. Studies reveal structure of EV71, a virus causing childhood illnesses
2. Crystal structure of archael chromatin clarified in new study
3. Scientists produce eye structures from human blood-derived stem cells
4. Autism risk gene linked to differences in brain structure
5. Expedition to undersea mountain yields new information about sub-seafloor structure
6. Mechanical properties and microstructure of cranial and beak bones of the woodpecker and the lark
7. Psychiatric medication effects on brain structure
8. CSHL researchers solve structure of human protein critical for silencing genes
9. Study provides new insights into structure of heart muscle fibers
10. Detector of DNA damage: Structure of a repair factor revealed
11. Structure of RNAi complex now crystal clear
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/28/2017)... , March 28, 2017 The ... Hardware (Camera, Monitors, Servers, Storage Devices), Software (Video Analytics, ... Region - Global Forecast to 2022", published by MarketsandMarkets, ... 2016 and is projected to reach USD 75.64 Billion ... and 2022. The base year considered for the study ...
(Date:3/24/2017)... 24, 2017 The Controller General of Immigration from ... Abdulla Algeen have received the prestigious international IAIR Award for the ... Continue Reading ... ... Controller Abdulla Algeen (small picture on the right) have received the IAIR ...
(Date:3/23/2017)... The report "Gesture Recognition and Touchless Sensing Market by Technology (Touch-based ... to 2022", published by MarketsandMarkets, the market is expected to be worth USD ... 2022. Continue Reading ... ... ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. ... Cancer Research, London (ICR) and University ... SKY92, SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma ... MUK nine . The University of Leeds ... partly funded by Myeloma UK, and ICR will perform the ...
(Date:10/10/2017)... ... 2017 , ... San Diego-based team building and cooking events company, Lajollacooks4u, has ... The bold new look is part of a transformation to increase awareness, appeal to ... period. , It will also expand its service offering from its signature gourmet cooking ...
(Date:10/10/2017)... 10, 2017 International research firm Parks Associates announced ... at the TMA 2017 Annual Meeting , October 11 in ... residential home security market and how smart safety and security products impact ... Parks Associates: Smart Home ... "The residential security market has ...
(Date:10/9/2017)... DIEGO , Oct. 9, 2017  BioTech ... biological mechanism by which its ProCell stem cell ... critical limb ischemia.  The Company, demonstrated that treatment ... amount of limbs saved as compared to standard ... the molecule HGF resulted in reduction of therapeutic ...
Breaking Biology Technology: