Johns Hopkins Medical LogoEvery instant, millions of body cells are claimed to impeccably divvy up their genes and pinch flawlessly in half to apparently form two alike progeny for the replacement of tissues and organs. All this even as they supposedly bump, get jammed, and compress through infinitesimally small spaces that could disfigure their shapes.

Scientists from Johns Hopkins, working with the simplest of organisms, have apparently found the molecular sensor that may allow cells not only to ‘feel’ changes to their neat shapes, but also to apparently alter themselves back into ready-to-split proportion. The experts demonstrated that two force-sensitive proteins apparently gather at the sites of cell-shape disturbances and assist first to supposedly sense the changes and then to re-sculpt the cells. The proteins myosin II and cortexillin I may supervise and correct shape changes in order to apparently guarantee smooth division.

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

Robinson observed that defective cell division may put organisms, including people, on the trail to diseases such as cancer. An improved understanding of how cells react to mechanical stress on their shapes may present new targets for both diagnosing and treating such diseases.

Working with resilient, single-celled protozoa that may shift and split likewise to human cells, the scientists observed through microscopes while they claimed to distort the shape of the cells with a small tool like a soda straw. It apparently sucks in on the cell surface and could form unclear shapes.

Robinson mentioned, “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.”

The scientists supervised the actions of fluorescent-tagged myosin II and cortexillin I, once the cells were apparently distorted. Myosins, which may usually collect in the middle of cells during division to assist power that process, apparently gathered instead at the sites of disturbances made by the micropipette. Also accrual with myosin could be cortexillin I, a so-called actin-crosslinking protein that, like glue, supposedly holds the toothpick-like filaments of a cell’s housing together.

In the experiments, as soon as the two proteins supposedly hoarded to a particular level, the cells apparently constricted, evading the pipettes and assuming their original shapes. After the cells righted themselves, the proteins may realign along the cells’ midlines and could pinch to split symmetrically into two daughter cells.

The expermiment was repeated by the experts via cells engineered to supposedly require myosin II and then again with cells apparently wanting cortexillin I. It was found that cortexillin I may respond to deformations except when myosin II was supposedly removed and myosin II could respond to deformations except when cortexillin I was apparently removed.

Robinson is of the opinion that it’s clear that the two may need each other to operate as a cellular mechanosensor.

This study was published in the September issue of Current Biology.