Navigation Links
Dividing cells 'feel' their way out of warp

Every moment, millions of a body's cells flawlessly divvy up their genes and pinch perfectly in half to form two identical progeny for the replenishment of tissues and organs even as they collide, get stuck, and squeeze through infinitesimally small spaces that distort their shapes.

Now Johns Hopkins scientists, working with the simplest of organisms, have discovered the molecular sensor that lets cells not only "feel" changes to their neat shapes, but also to remodel themselves back into ready-to-split symmetry. In a study published September 15 in Current Biology, the researchers show that two force-sensitive proteins accumulate at the sites of cell-shape disturbances and cooperate first to sense the changes and then to resculpt the cells. The proteins myosin II and cortexillin I monitor and correct shape changes in order to ensure smooth division.

"What we found is an exquisitely tuned mechanosensory system that keeps the cells shipshape so they can divide properly," says Douglas N. Robinson, Ph.D., an associate professor of Cell Biology, Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine.

Faulty cell division can put organisms, including people, on the pathway to diseases such as cancer, Robinson notes, and a better understanding of how cells respond to mechanical stress on their shapes could present new targets for both diagnosing and treating such diseases.

Working with hardy, single-celled protozoa that move and divide similarly to human cells, the scientists watched through microscopes while they deformed the cells' shapes with a tiny instrument that, like a soda straw, sucks in on the cell surface and creates distorted shapes.

"This particular method, based on a very old principle that dates back to Archimedes, enables us to deform cells without killing them, much in the same way that natural processes in the body constantly assault them, Robinson says."

Once the cells were warped, the scientists monitored the movements of fluorescent-tagged myosin II and cortexillin I. Myosin, which normally accumulates in the middles of cells during division to help power that process, collected instead at the sites of disturbances made by the micropipette. Also amassing with myosin was cortexillin I, a so-called actin-crosslinking protein that, like glue, holds the toothpick-like filaments of a cell's housing together.

In the experiments, as soon as the two proteins accumulated to a certain level, the cells contracted, escaping the pipettes and assuming their original shapes. After the cells righted themselves, the proteins realigned along the cells' midlines and pinched to divide symmetrically into two daughter cells.

The researchers repeated the experiment using cells engineered to lack myosin II and then again with cells lacking cortexillin I. They discovered that cortexillin I responded to deformations except when myosin II was removed, and myosin II responded to deformations except when cortexillin I was removed.

"It's clear that the two need each other to operate as a cellular mechanosensor," Robinson says.


Contact: Maryalice Yakutchik
Johns Hopkins Medical Institutions

Related biology news :

1. Carbon nanotubes could make efficient solar cells
2. Size of fat cells and waist size predict type 2 diabetes in women
3. Pandemic flu can infect cells deep in the lungs, says new research
4. Individual cells isolated from biological clock can keep daily time, but are unreliable
5. Researchers find first evidence of virus in malignant prostate cells
6. Liposuction leftovers easily converted to IPS cells, Stanford study shows
7. Making more efficient fuel cells
8. UT Southwestern researchers examine mechanisms that help cancer cells proliferate
9. Lower-cost solar cells to be printed like newspaper, painted on rooftops
10. Glow-in-the-dark red blood cells made from human stem cells
11. When cells run out of fuel
Post Your Comments:
Related Image:
Dividing cells 'feel' their way out of warp
(Date:6/7/2016)... 2016  Syngrafii Inc. and San Antonio Credit ... includes integrating Syngrafii,s patented LongPen™ eSignature "Wet" solution ... will result in greater convenience for SACU members ... maintaining existing document workflow and compliance requirements. ... Highlights: ...
(Date:6/2/2016)...   The Weather Company , an IBM Business (NYSE: ... capability in which consumers will be able to interact with ... via voice or text and receive relevant information about the ... Marketers have long sought an advertising solution that can create ... relevant and valuable; and can scale across millions of interactions ...
(Date:5/24/2016)... , May 24, 2016 Ampronix facilitates superior patient care by providing ...  3D medical LCD display is the latest premium product recently added to the range ... ... ... Sony 3d Imaging- LCD Medical Display- Ampronix News ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... ... 24, 2016 , ... While the majority of commercial spectrophotometers and fluorometers use ... 6000i models are higher end machines that use the more unconventional z-dimension of 20mm. ... from the bottom of the cuvette holder. , FireflySci has developed several Agilent ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one of ... their brand, UP4™ Probiotics, into Target stores nationwide. The company, which has been ... Target to its list of well-respected retailers. This list includes such fine stores ...
(Date:6/23/2016)... , June 23, 2016 A person commits a ... crime scene to track the criminal down. An ... Food and Drug Administration (FDA) uses DNA evidence to track ... Sound far-fetched? It,s not. The FDA has increasingly ... support investigations of foodborne illnesses. Put as simply as possible, ...
(Date:6/23/2016)... , June 23, 2016  The Prostate Cancer Foundation (PCF) is ... treatments and faster cures for prostate cancer. Members of the Class of 2016 ... countries. Read More About the Class of 2016 PCF ... ... ...
Breaking Biology Technology: