Navigation Links
Dividing cells 'feel' their way out of warp
Date:9/10/2009

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
myakutc1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert  

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:
*Name:
*Comment:
*Email:
Related Image:
Dividing cells 'feel' their way out of warp
(Date:4/13/2017)... , April 13, 2017 According to a ... Identity Authentication, Identity Analytics, Identity Administration, and Authorization), Service, Authentication Type, Deployment ... the IAM Market is expected to grow from USD 14.30 Billion in ... Rate (CAGR) of 17.3%. ... MarketsandMarkets Logo ...
(Date:4/11/2017)... No two people are believed to ... York University Tandon School of Engineering and Michigan ... partial similarities between prints are common enough that ... and other electronic devices can be more vulnerable ... in the fact that fingerprint-based authentication systems feature ...
(Date:4/5/2017)... , April 5, 2017  The Allen Institute for ... Cell Explorer: a one-of-a-kind portal and dynamic digital window ... imaging data, the first application of deep learning to ... stem cell lines and a growing suite of powerful ... for these and future publicly available resources created and ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... , ... AMRI, a global contract research, development and manufacturing ... and quality of life, will now be offering its impurity solutions as a ... requirements for all new drug products, including the finalization of ICH M7 earlier ...
(Date:10/11/2017)... ... 2017 , ... ComplianceOnline’s Medical Device Summit is back for its 4th year. ... San Francisco, CA. The Summit brings together current and former FDA office bearers, regulators, ... government officials from around the world to address key issues in device compliance, quality ...
(Date:10/11/2017)... ... 2017 , ... A new study published in Fertility and ... in vitro fertilization (IVF) transfer cycles. The multi-center matched cohort study ... comparing the results from the fresh and frozen transfer cohorts, the authors of ...
(Date:10/10/2017)... ... , ... Dr. Bob Harman, founder and CEO of VetStem Biopharma, Inc. ... The event entitled “Stem Cells and Their Regenerative Powers,” was held on August ... MPVM was joined by two human doctors: Peter B. Hanson, M.D., Chief of Orthopedic ...
Breaking Biology Technology: