Just as human relationships are a two-way street, fusion between cells requires two active partners: one to send protrusions into its neighbor, and one to hold its ground and help complete the process. Researchers have now found that one way the receiving cell plays its role is by having a key structural protein come running in response to pressure on the cell membrane, rather than waiting for chemical signals to tell it that it's needed. The study, which helps open the curtain on a process relevant to muscle formation and regeneration, fertilization, and immune response, appears in the March 9 issue of the journal Developmental Cell.
"We knew that in cell fusion, one cell attacks its fusion partner, but we didn't know what the other cell was doing," says Elizabeth Chen, Ph.D. , an associate professor of molecular biology and genetics at the Johns Hopkins University School of Medicine. "Now we know that the other cell is putting up some resistance."
The merging of two cells, which is crucial to conception, development and physiology of complex organisms, was long thought to be a symmetrical process, where two cells contribute equally. But two years ago, Chen's research group showed that, in fact, one of the fusion partners initiates the process by extending fingerlike protrusions into the other partner.
For this study, Chen's group and collaborators focused on the receiving partner. Using fruit fly embryos and lab-grown fly cells that were induced to fuse, they saw that in the areas where the attacking cells drilled in, the receiving cells quickly fortified their cellular skeletons, effectively pushing back.
"We think that by stiffening its skeleton in this way, the receiving cell avoids moving away from the attacking cell, in which case fusion couldn't occur," Chen says. "The interplay of the two cells pushing against one another brings the two cell membranes into close proximity so that fusion can proceed."
But how were the cellular skeleton's building blocks, such as the protein myosin II, being summoned to the fusion site? To find out, Chen's group altered cell surface proteins that are known to relay chemical signals in the receiving cells of fly embryos.
"In most of the cells, we still saw myosin swarm to the fusion site, despite the fact that chemical signaling had been disabled," Chen says. In other words, myosin is able to sense and respond to pressure on the outside of the cell. Myosin's "mechanosensory" response was also seen when Chen's collaborators used either a tiny pipette to apply a pulling force or a tiny probe to apply a pushing force to lab-grown cells.
There is much still to learn about the cell fusion process, however. Next, Chen's group plans to examine how pressure is conveyed from the cell membrane to its skeleton and which proteins on the membrane facilitate fusion.
Other authors on the paper are Ji Hoon Kim, Yixin Ren, Shuo Li, Yee-Seir Kee, Shiliang Zhang and Douglas N. Robinson of The Johns Hopkins University; Win Pin Ng, Sungmin Son and Daniel A. Fletcher of the University of California, Berkeley; and Guofeng Zhang of the National Institute of Biomedical Imaging and Bioengineering.
Read the Developmental Cell article. http://www.
Shawna Williams | EurekAlert!
Kidney tumor: Genetic trigger discovered
18.06.2018 | Julius-Maximilians-Universität Würzburg
New type of photosynthesis discovered
18.06.2018 | Imperial College London
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering
18.06.2018 | Life Sciences