Navigation Links
Nicotine rush hinges on sugar in neurons

When nicotine binds to a neuron, how does the cell know to send the signal that announces a smoker’s high"

As with other questions involving good sensations, the answer appears to be sugar.

A University of Southern California study appearing with a commentary in Nature Neuroscience online proposes a role for sugar as the hinge that opens a gate in the cell membrane and brings news of nicotine’s arrival.

Structural biologist Raymond Stevens of The Scripps Research Institute, who was not involved in the study, called it “a landmark accomplishment for the fields of structural biology and neuronal cell signaling.”

Besides substance addiction, Stevens pointed to epilepsy, schizophrenia and depression as targets for improved drugs that could result from the study’s findings.

The study provides the first detailed look at part of the mouse nicotinic acetylcholine receptor (nAChR), one in a large and important group of molecules, known as ion channel proteins, that allow signals to pass between neurons.

The results reveal an important role for the sugar molecules in such proteins.

“Our studies fill a major gap in the field and set a new paradigm,” said Lin Chen, associate professor of molecular and computational biology at USC.

Many existing theories, which do not consider sugar’s role, are probably incomplete, Chen said.

The debate over how signals pass from the outside of a cell to the inside is a long-standing one.

Some researchers had suggested that when a chemical such as nicotine binds to an ion channel protein on the cell surface, the protein starts a “conformational wave” that propagates a signal through the protein body to the cell membrane, Chen said.

But the molecular basis of such a wave in nAChR or any other protein has not been clearly established.

Instead, the Chen group’s study of crystal structure suggested a simple mechanical role for sugar molecule s attached to the surface of the receptor.

“They serve as the link between the neurotransmitter binding site and the membrane region where the gate is located,” Chen said.

“The sugar is kind of like a hinge. It’s pulling the door open and closed.”

Cutting the sugar chains stopped the gate’s operation, according to Chen, who said, “The sugar is critical, in my opinion.”

The researchers also found a water molecule deep in the receptor’s core – significant because proteins normally are filled with hydrophobic (water repellent) matter that helps the structure hold its shape, Chen said.

The water molecule may enable the receptor to alter its shape in counterbalance to the bending hinge, said Chen, who explained, “Think of it as a lubricant.”

Previously studied “homologs” of nAChR – proteins that share its structure but not its signaling function – are entirely hydrophobic, Chen said, supporting the theory that the buried water molecule plays a functional role.

Chen called the group’s Nature Neuroscience study “one of the few times that you felt that you connected the dots.”

The study also represents a tour de force of protein crystallography. Homologs of nAChR had been studied at the atomic scale, but not the receptor itself.


'"/>

Source:University of Southern California


Related biology news :

1. Successful lung cancer surgery not enough to break nicotine dependence in many smokers
2. Nicotine triggers the same brain reward circuitry as opiates
3. Prenatal nicotine exposure reduces breathing response of newborns...
4. Nicotine exposure during development leads to hearing problems
5. Blood test predicts success of quitting smoking using the nicotine patch
6. Dissecting the machinery of nicotines reward
7. Smokers invite to test vaccine against nicotine addiction
8. New research identifies gene important for nicotines effects on the brain
9. Re-analysis of cigarettes confirms tobacco companies increased addictive nicotine 11 percent
10. Mechanism of nicotines learning effects explored
11. Children of smokers have more than 5 times higher levels of a nicotine toxin
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: