Chemical engineers from
Through this new method, the researchers found that cells stir their interiors using the same motor proteins that serve in muscle contraction.
The study, which sheds new light on biological transport mechanisms in cells, appears this week in Science.
The team attached carbon nanotubes to transport molecules known as kinesin motors to visualize and track them as they moved through the cytoplasm of living cells.
"I am amazed how versatile carbon nanotubes are," said co-author
"Any probe that can hitch the length and breadth of the cell, rough it, slum it, struggle against terrible odds, win through and still know where its protein is, is clearly a probe to be reckoned with," said lead author
"In fact, the exceptional stability of these probes made it possible to observe intracellular motions from times as short as milliseconds to as long as hours," she said.
For long-distance transport, such as along the long axons of nerve cells, cells usually employ motor proteins tied to lipid vesicles, the cell's "cargo containers." This process involves considerable logistics: Cargo needs to be packed, attached to the motors and sent off in the right direction.
"This research has helped uncover an additional, much simpler mechanism for transport within the cell interior," said principal investigator
The researchers showed the same type of motor protein used for muscle contraction is responsible for stirring. They reached this conclusion after exposing the cells to drugs that suppressed these specific motor proteins. The tests showed that the stirring was suppressed as well.
The mechanical cytoskeleton of cells consists of networks of protein filaments, like actin. Within the cell, the motor protein myosin forms bundles that actively contract the actin network for short periods. The researchers found random pinching of the elastic actin network by many myosin bundles resulted in the global internal stirring of the cell. Both actin and myosin play a similar role in muscle contraction.
The highly accurate measurements of internal fluctuations in the cells were explained in a theoretical model developed by VU co-author
"The new discovery not only promotes our understanding of cell dynamics, but also points to interesting possibilities in designing 'active' technical materials," said Fakhri, who will soon join the
Co-authors of the study include graduate student
TNS 18DejucosGrace-140530-30FurigayJane-4750939 30FurigayJane
Most Popular Stories
- Neighbor Warns Chris Brown to Stay Off His Property
- Venezuelan Officials Banned From Traveling in U.S.
- WWE Showing Off Its Muscles
- As Jobs Market Strengthens, Many Don't Feel It
- Target Taps Pepsi Exec as New CEO
- Islamic State Fights for Control of Syrian Oil Wealth
- House Votes to Sue Obama
- Hispanic Arts Leaders Unite Across the Border
- Homeowners More Satisfied With Mortgage Servicers
- Adrienne Bailon Disses Ex-Lover Rob Kardashian