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 July 31, 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 July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) — Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) — With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) — Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
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