Navigation Links
Researchers explain how railways within cells are built in order to transport essential cargos
Date:9/2/2011

Every cell in the human body contains a complex system to transport essential cargoes such as proteins and membrane vesicles, from point A to point B. These tiny molecular motor proteins move at blistering speeds on miniature railways carrying components of the cell to their proper destinations. But just how cells construct these transport railways to fit precisely inside of confined spaces of the individual cells has been a complex question, as it is critical that these railways do not grow too long or come up too short, as that would cause a misdirection of the proteins being transported.

Bruce Goode, professor of biology, working in collaboration with the labs of Laurent Blanchoin (Grenoble, France) and Roland Wedlich-Soldner (Munich, Germany), have come one step closer to understanding the elusive mechanics of this process.

In a recent paper published in Developmental Cell, a team led by Goode's Ph.D. student Melissa Chesarone-Cataldo shows that the length of the railways is controlled by one of its "passengers," which pauses during the journey to communicate with the machinery that is building the railways.

"The frequency of these chats between the passengers and builders may provide the feedback necessary to say a railway is long enough, and construction should now slow down," says Goode.

Much like a real construction site, a system must be in place with roadways and transporters to move the building materials. In this case, cellular proteins called actin cables act as the roadways, and the transporters are myosin molecules, nanoscale motor proteins that rapidly deliver critical cargoes to one end of a cell. Each cable is assembled from hundreds or thousands of copies of the actin, which is called a helical filament.

Nine years ago, Goode and his colleagues discovered that a family of proteins called formins stimulate the rapid growth of actin filaments. Recently, the team began to question how a cell controls the power of formins, which tell them when to speed up, when to slow down, when to stop altogether.

Enter Smy1, a myosin-passenger protein.

Goode and his colleagues hypothesized that a passenger protein like Smy1 would provide the perfect mechanism for slowing down formins when roadways are longer and would be carrying more passengers. They tested their theory in yeast cells, where formins construct actin cables that transport building materials essential for cell growth and division. As Goode says, they struck gold.

When they deleted the gene for Smy1, cables grew abnormally fast and hit the back of the cell, buckling and misdirecting transport. When they purified Smy1 and placed it in a test tube with formins they discovered that Smy1 slows down actin filament growth.

To further explore, they tagged Smy1 in living cells and learned that Smy1 molecules are carried on cables by myosin to the formin, where they pause for 1-2 seconds to give formins the message to slow down.

Goode says their working model illustrates that as a cable grows longer, it loads up more and more Smy1 molecules, which are transported on the cable to send a message to the formin to slow down.

"This prevents overgrowth of longer cables that are nearing the back of the cell, but allows rapid growth of the shorter cables," says Goode.

This paper will help scientists understand the general mechanisms that are used for directing cell shape and division. The next challenge says Goode, is "to find out whether related mechanisms are used to control formins in mammalian cells and understand the physiological consequences of disrupting those mechanisms."


'/>"/>

Contact: Susan Chaityn Lebovits
lebovits@brandeis.edu
781-736-4027
Brandeis University
Source:Eurekalert

Related biology news :

1. NC State researchers get to root of parasite genome
2. Researchers find animal with ability to survive climate change
3. Researchers find an essential gene for forming ears of corn
4. Researchers note differences between people and animals on calorie restriction
5. Researchers study acoustic communication in deep-sea fish
6. Researchers discover that growing up too fast may mean dying young in honey bees
7. Researchers study how pistachios may improve heart health
8. UI researchers find potentially toxic substance present in Chicago air
9. Researchers develop new self-training gene prediction program for fungi
10. Case Western Reserve University researchers track Chernobyl fallout
11. Childrens National researchers develop novel anti-tumor vaccine
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/20/2016)... 20, 2016  VoiceIt is excited to announce ... By working together, VoiceIt and VoicePass ... and VoicePass take slightly different approaches to voice ... security and usability. ... new partnership. "This marketing and technology ...
(Date:5/12/2016)... May 12, 2016 WearablesResearch.com , a ... the overview results from the Q1 wave of its ... wave was consumers, receptivity to a program where they ... a health insurance company. "We were surprised ... says Michael LaColla , CEO of Troubadour Research, ...
(Date:5/3/2016)... 3, 2016  Neurotechnology, a provider of high-precision ... Automated Biometric Identification System (ABIS) , a complete ... MegaMatcher ABIS can process multiple complex biometric transactions ... of fingerprint, face or iris biometrics. It leverages ... and MegaMatcher Accelerator , which have been ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... FRANCISCO , June 23, 2016   EpiBiome ... has secured $1 million in debt financing from Silicon ... ramp up automation and to advance its drug development ... its new facility. "SVB has been an ... beyond the services a traditional bank would provide," said ...
(Date:6/23/2016)...  Blueprint Bio, a company dedicated to identifying, protecting ... has closed its Series A funding round, according to ... "We have received a commitment from Forentis Fund that ... meet our current goals," stated Matthew Nunez . ... complete validation on the current projects in our pipeline, ...
(Date:6/23/2016)... ... June 23, 2016 , ... Velocity Products, ... tools designed, tuned and optimized exclusively for Okuma CNC machining centers at The ... of a collaboration among several companies with expertise in toolholding, cutting tools, machining ...
(Date:6/22/2016)... NEW YORK , June 22, 2016 /PRNewswire/ ... the growing next generation sequencing (NGS) market include ... adoption of smaller sequencers.  More accessible and affordable ... led to growing demand for consumables including sample ... The Market for Sample Preparation for Next ...
Breaking Biology Technology: