Can a cell sense its own shape? Working in the Marine Biological Laboratory's Whitman Center, scientists from Dartmouth College developed an ingenious experiment to ask this question. Their conclusion - Yes - is detailed in a recent paper in the Journal of Cell Biology.
"Cells adopt diverse shapes that are related to how they function. We wondered if cells have the ability to perceive their own shapes, specifically, the curvature of the [cell] membrane," says Drew Bridges, a Ph.D. candidate in the laboratory of Amy Gladfelter, associate professor of biological sciences at Dartmouth College and a scientist in the MBL's Whitman Center.
The team focused on the septins, proteins that are usually found near micron-scaled curves in the cell membrane, such as the furrow that marks where the cell will pinch together and divide.
Using live-cell imaging at the MBL, they noticed that septins in a novel model system, the fungus Ashbya gossypii, tended to congregate on fungus branches where curvature was highest.
They then decided to recreate this natural phenomenon in the lab, using artificial materials they could measure more easily than living cells. Using precisely scaled glass beads coated with lipid membranes, they discovered that septin proteins preferred curves in the 1-3 micron range.
They got the same result using human or fungal septins, suggesting that this phenomenon is evolutionarily conserved.
"This ability of septins to sense micron-scaled cell curvature provides cells with a previously unknown mechanism for organizing themselves," Bridges says.
The idea for the glass bead experiment came from "many rich intellectual discussions with other members of the MBL community," says Bridges, who has accompanied Gladfelter to the MBL each summer since 2012. "Both our collaborations and the imaging resources at MBL were central to this work."
Bridges, A. A., Jentzsch, M.S., Oakes, P.W., Occhipinti, P., and Gladfelter, A.S. (2016) Micron-scale plasma membrane curvature is recognized by the septin cytoskeleton. J Cell Biol 213:23-32, doi:10.1083/jcb.201512029.
The Marine Biological Laboratory (MBL) is dedicated to scientific discovery - exploring fundamental biology, understanding marine biodiversity and the environment, and informing the human condition through research and education. Founded in Woods Hole, Massachusetts in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.
Diana Kenney | EurekAlert!
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy