Featured Research

from universities, journals, and other organizations

Protein folding: Understanding the dance of the chaperones

Date:
March 8, 2012
Source:
Max-Planck-Gesellschaft
Summary:
Proteins are the molecular building blocks and machinery of cells and involved in practically all biological processes. To fulfill their tasks, they need to be folded into a complicated three-dimensional structure. Scientists have now analyzed one of the key players of this folding process: the molecular chaperone DnaK.

The chaperone DnaK binds to new proteins and mediates their folding. Proteins it cannot fold, DnaK transports to GroEL, a highly specialised folding machine.
Credit: MPI of Biochemistry

Proteins are the molecular building blocks and machinery of cells and involved in practically all biological processes. To fulfil their tasks, they need to be folded into a complicated three-dimensional structure. Scientists from the Max Planck Institute of Biochemistry (MPIB) in Martinsried near Munich, Germany, have now analysed one of the key players of this folding process: the molecular chaperone DnaK. "The understanding of these mechanisms is of great interest in the light of the many diseases in which folding goes awry, such as Alzheimer's or Parkinson's," says Ulrich Hartl, MPIB director.

The work of the researchers has now been published in Cell Reports.

Proteins are responsible for almost all biological functions. The cells of the human body continuously synthesize thousands of different proteins in the form of amino acid chains. In order to be biologically useful, these chains must fold into a complex three-dimensional pattern. When this difficult process goes wrong, it can lead to useless or even dangerous protein clumps. All cells, from bacteria to human, have therefore developed a network of molecular chaperones, proteins themselves, which help other proteins to fold properly.

MPIB scientists have now investigated the organisation of this network in the bacterium Escherichia coli. Using proteomic analyses they show how different chaperones cooperate during the folding process. "We identified the Hsp70 protein DnaK as the central player of the network," explains Ulrich Hartl. "It functions as a kind of turntable." DnaK binds to about 700 different protein chains as they are synthesised. Furthermore, DnaK mediates the folding of most of these protein chains. Those it cannot fold are transferred to yet another chaperone, the barrel-shaped GroEL. GroEL is a highly specialised folding machine. It forms a nano-cage in which a single protein chain is temporarily enclosed and allowed to fold while protected from external influences.

Disruptions in the Chaperone Network

The researchers also investigated what happens when the chaperone network is disturbed. For example, when GroEL is removed from the cells, its client proteins accumulate on DnaK, which then shuttles them to proteases to be decomposed. "Apparently, DnaK realises that the attached protein chains will never be able to mature into useful molecules," says the biochemist. Similar but even more complicated chaperone networks control the proteome of human cells. Understanding these reactions is of great interest in the light of the many neurodegenerative diseases in which folding goes awry.


Story Source:

The above story is based on materials provided by Max-Planck-Gesellschaft. Note: Materials may be edited for content and length.


Journal Reference:

  1. Giulia Calloni, Taotao Chen, Sonya M. Schermann, Hung-chun Chang, Pierre Genevaux, Federico Agostini, Gian Gaetano Tartaglia, Manajit Hayer-Hartl, F. Ulrich Hartl. DnaK Functions as a Central Hub in the E. coli Chaperone Network. Cell Reports, 08 March 2012 DOI: 10.1016/j.celrep.2011.12.007

Cite This Page:

Max-Planck-Gesellschaft. "Protein folding: Understanding the dance of the chaperones." ScienceDaily. ScienceDaily, 8 March 2012. <www.sciencedaily.com/releases/2012/03/120308132705.htm>.
Max-Planck-Gesellschaft. (2012, March 8). Protein folding: Understanding the dance of the chaperones. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2012/03/120308132705.htm
Max-Planck-Gesellschaft. "Protein folding: Understanding the dance of the chaperones." ScienceDaily. www.sciencedaily.com/releases/2012/03/120308132705.htm (accessed April 16, 2014).

Share This



More Plants & Animals News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
In Washington, a Push to Sterilize Stray Cats

In Washington, a Push to Sterilize Stray Cats

AFP (Apr. 14, 2014) To curb the growing numbers of feral cats in the US capital, the Washington Humane Society is encouraging residents to set traps and bring the animals to a sterilization clinic, after which they are released.. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
After Attack, Officials Kill 5 Bears in Florida

After Attack, Officials Kill 5 Bears in Florida

AP (Apr. 14, 2014) Florida wildlife officials say they have killed five bears following an attack on a woman in a suburban subdivision in central Florida. Forty-five year-old Terri Frana was attacked by a large bear in her driveway Saturday. (April 14) Video provided by AP
Powered by NewsLook.com
Uruguay Opens Its First Cannabis Library

Uruguay Opens Its First Cannabis Library

AFP (Apr. 13, 2014) Uruguay opened its first Cannabis Library in Montevideo on Saturday, where people can come and read books on cannabis or take classes on how to grow the plant or even how to cook with it. Duration: 01:20 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:
from the past week

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