Featured Research

from universities, journals, and other organizations

Insight into the dazzling impact of insulin in cells

Date:
May 21, 2013
Source:
Garvan Institute of Medical Research
Summary:
Australian scientists have charted the path of insulin action in cells in precise detail like never before. This provides a comprehensive blueprint for understanding what goes wrong in diabetes.

Australian scientists have charted the path of insulin action in cells in precise detail like never before. This provides a comprehensive blueprint for understanding what goes wrong in diabetes.

Related Articles


The breakthrough study, conducted by Sean Humphrey and Professor David James from Sydney's Garvan Institute of Medical Research, is now published in the early online edition of the journal Cell Metabolism.

First discovered in 1921, the insulin hormone plays a very important role in the body because it helps us lower blood sugar after a meal, by enabling the movement of sugar from the blood into cells. Until now, although scientists have understood the purpose of insulin at a broad level, they have struggled to understand exactly how it achieves its task.

The latest analytical devices called mass spectrometers now provide the tool that has been missing -- the means of looking into the vastly complex molecular maze that exists in every single cell in the human body.

These powerful devices have opened up a field known as 'proteomics', the study of proteins on a very large scale. Proteins represent the working parts of cells, using energy to perform all essential functions such as muscle contraction, heartbeat or even memory.

Each cell houses multiple copies of between 10,000 and 12,000 protein types, which communicate with each other using various methods, the most common of which is a process known as 'phosphorylation'. Phosphate molecules are deliberately added to proteins in order to convey information, or else change the protein's function.

Each of the protein types in a cell has up to 20 potential 'phosphorylation sites', regions to which a phosphate molecule can be added. This pushes the total number of possible cell states from one moment to the next into the billions.

The authors discovered 37,248 phosphorylation sites on 5,705 different proteins, 15% of which changed in response to insulin.

"Until this study, we did not really appreciate the scale and complexity of insulin regulation," said lab leader Professor David James.

"When insulin is released from the pancreas after we eat, it travels to cells and initiates a cascade of protein phosphorylation, literally millions of interactions, some instantaneous, some taking minutes or hours. The process is so precise and intricate, and at the same time so monumental in its scope, that it's truly astounding."

Sean Humphrey, who undertook the mass spectrometry work, discovered over 1,500 phosphorylation sites that respond to insulin, and described the process as "eye opening."

"When you consider that phosphorylation is only one type of signaling -- acetylation and methylation are other forms -- you begin to understand the kind of complexity that faces us," he said.

In addition to cataloguing the phosphoproteome of the fat cell, the authors discovered novel regulation of a protein called 'SIN1', key to our understanding of the chain of events that occurs during insulin signaling. They have also described the mechanisms by which SIN1 influences other influential proteins within the cell, in particular one known as Akt.

"Sean's study has shed new light on how one of the most important regulators in the cell -- a protein called Akt -- is itself regulated," said Professor James.

"Akt not only plays a role in diabetes, but also in cancer and other diseases, and the discovery of SIN1 phosphorylation gives us useful new insights into how Akt actually functions in a cell."

"These large scale approaches are providing us with new levels of understanding of human biology that we would never have anticipated. Without the mass spectrometer, we could not have discovered the importance of SIN1 phosphorylation in the overall insulin signaling process."

"It's an important lesson about the usefulness of this technology in allowing us to discover new things about the cell and how it regulates itself."


Story Source:

The above story is based on materials provided by Garvan Institute of Medical Research. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sean J. Humphrey, Guang Yang, Pengyi Yang, Daniel J. Fazakerley, Jacqueline Stöckli, Jean Y. Yang, David E. James. Dynamic Adipocyte Phosphoproteome Reveals that Akt Directly Regulates mTORC2. Cell Metabolism, 2013; DOI: 10.1016/j.cmet.2013.04.010

Cite This Page:

Garvan Institute of Medical Research. "Insight into the dazzling impact of insulin in cells." ScienceDaily. ScienceDaily, 21 May 2013. <www.sciencedaily.com/releases/2013/05/130521105704.htm>.
Garvan Institute of Medical Research. (2013, May 21). Insight into the dazzling impact of insulin in cells. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2013/05/130521105704.htm
Garvan Institute of Medical Research. "Insight into the dazzling impact of insulin in cells." ScienceDaily. www.sciencedaily.com/releases/2013/05/130521105704.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
WHO Says Male Ebola Survivors Should Abstain From Sex

WHO Says Male Ebola Survivors Should Abstain From Sex

Newsy (Nov. 28, 2014) — WHO cites four studies that say Ebola can still be detected in semen up to 82 days after the onset of symptoms. Video provided by Newsy
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins