Navigation Links
Spiral constriction -- how dynamin mediates cellular nutrient uptake
Date:9/20/2011

Dr. Katja Flber and Professor Oliver Daumke, structural biologists at the Max Delbrck Center for Molecular Medicine (MDC) Berlin-Buch, together with researchers from Freie Universitt (FU) Berlin, have determined the molecular structure of dynamin, a 'wire-puller' that mediates nutrient uptake into the cell. Since pathogens such as HIV can also enter the body's cells in this way, understanding the underlying molecular mechanisms can potentially open up new approaches for medical applications (Nature, DOI: 10.1038/nature10369)*.

Many nutrients pass from the blood through cell membrane channels into the body cells. However, appropriate channels do not exist for all nutrients. For example, iron binds outside the cell to a large transport molecule and is imported by other means, via endocytosis, into the cell. The cargo-containing transport molecules bind to the cell membrane, which invaginates inward. The iron molecules along with their transporters are taken up in a small membrane bubble (vesicle) into the cell and released there.

An important 'wire-puller' of endocytosis is the protein molecule dynamin. And that in the most literal sense of the word: If a vesicle forms, the dynamin molecules self-assemble and form a spiral around the neck of the vesicle. Dynamin functions like a small motor: It uses the energy of the cell's GTP to pull the spiral together, constricting the neck of the vesicle so that it detaches from the cell membrane.

The molecular details of this 'pull' mechanism around the vesicle neck were previously unknown. In their present study, MDC structural biologists Professor Daumke and Dr. Flber, together with the endocytosis researcher Professor Volker Haucke and the bioinformatician Dr. Frank No of FU Berlin, provide fundamental insights into this process. Using X-ray diffraction analysis, they succeeded in building a structural model of dynamin. For this study it was necessary to produce protein crystals of dynamin. To achieve this, the researchers utilized the insights gained in their previous study about a dynamin-related protein. From the X-ray diffraction pattern of these crystals the researchers were then able to derive a detailed picture of dynamin. "Now that we have an idea of how the dynamin molecule is structured, we can understand at the atomic level how the molecular motor dynamin functions," said Professor Daumke.

In addition to nutrient uptake, endocytosis is also essential for the transmission of signals between neighboring nerve cells and for the immune system. In this way, for example, macrophages engulf pathogens and make them harmless. Professor Daumke: "However, pathogens like HIV and influenza viruses utilize endocytosis to enter our body cells and to spread there. That is why it is important to gain an even more detailed understanding of the molecular 'pull' mechanism of dynamin during endocytosis. Then we can find potential approaches for medical applications especially for patients with muscle and nerve disorders associated with mutations in the dynamin gene." In future research projects funded by the German Research Foundation within the framework of the Collaborative Research Centers (SFB740 and SFB958), the MDC researchers intend to take an even closer look at dynamin. They want to find out what structural changes dynamin accomplishes when the cell's energy carrier GTP binds to the protein and the 'pull' mechanism is set in motion at the vesicle neck.


'/>"/>

Contact: Barbara Bachtler
bachtler@mdc-berlin.de
49-309-406-3896
Helmholtz Association of German Research Centres
Source:Eurekalert

Related biology news :

1. The cellular intricacies of cystic fibrosis
2. Cellular metabolism self-adapts to protect against free radicals
3. New cellular surprise may help scientists better understand human mitochondrial diseases
4. Cellular laser microsurgery illuminates research in vertebrate biology
5. Cellular stress can induce yeast to promote prion formation
6. Researchers provide means of monitoring cellular interactions
7. Development of a FRET sensor for real-time imaging of intracellular redox dynamics
8. How muscle develops: A dance of cellular skeletons
9. Harvard scientists see the early cellular cause of dry eye disease for the first time
10. Thalidomide shows efficacy as adjuvant therapy for hepatocellular carcinoma patients
11. WSU proves extracellular matrix tugging creates come hither stimulus for cancer migration
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... SAN FRANCISCO and BANGALORE, India ... part of EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... service provider, today announced a global partnership that ... convenient way to use mobile banking and payment services. ... Mobility is a key innovation area for financial services, but ...
(Date:4/26/2016)... and LONDON , ... Finacle, part of EdgeVerve Systems, a product subsidiary ... Onegini today announced a partnership to integrate the ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... provide their customers enhanced security to access and ...
(Date:4/19/2016)... 20, 2016 The new GEZE ... compact web-based "all-in-one" system solution for all door components. ... or the door interface with integration authorization management system, ... systems. The minimal dimensions of the access control and ... building installations offer considerable freedom of design with regard ...
Breaking Biology News(10 mins):
(Date:5/18/2016)... Calif. (PRWEB) , ... May 18, 2016 , ... ... awarded the Luis Villalobos Award to Cognition Therapeutics at the annual ACA Summit last ... company that is financed by one of ACA’s member angel groups. It is the ...
(Date:5/18/2016)... , May 18, 2016 The Biotech ... does not mean that there are no opportunities ahead. Today, ... Inc. (NASDAQ: THLD ), Seattle Genetics Inc. (NASDAQ: ... ), and Ophthotech Corp. (NASDAQ: OPHT ). Sign ... at: http://www.activewallst.com/ Threshold Pharmaceuticals ...
(Date:5/18/2016)... ... 18, 2016 , ... Every day, more than 5,400 ER ... Costing more than $56 billion in direct costs annually, asthma remains a critical ... the suffering associated with uncontrolled asthma can be overwhelmingly disproportionate and better managed,” ...
(Date:5/18/2016)... ... ... Ryan Benton was diagnosed with Duchenne Muscular Dystrophy (DMD) at the age ... DMD is a relatively common progressive genetic disorder, which causes aggressive deterioration of the ... He met with the founder of the Stem Cell Institute in Panama ...
Breaking Biology Technology: