Spectrin, F-actin, and associated proteins form a meshwork that supports and shapes the plasma membrane of red blood cells. A similar network underlies the membranes of other cell types, including lens fiber cells: elongated epithelial cells that encircle vertebrate lenses in concentric layers, appearing in cross section as tightly packed hexagons. Actin filaments within this membrane skeleton are stabilized by their association with members of the tropomyosin and tropomodulin families of actin-binding proteins.
In mice lacking tropomodulin1, gamma-tropomyosin was also lost from the membrane skeleton of lens fiber cells. F-actin and spectrin remained associated with the cell membrane, but gaps appeared in the usually continuous protein network, suggesting that the two actin-binding proteins stabilize a subset of actin filaments required to link the network together. Scanning electron microscopy revealed that fiber cell membrane protrusions, which interlock with neighboring cells, were distorted and irregularly arranged in the absence of tropomodulin1. And although the fiber cells appeared hexagonal when first forming at the lens' equator, they often became misshapen and disorganized as they matured and moved toward the lens' center.
Senior author Velia Fowler thinks that disruption of the spectrin–actin network alters the adhesive interactions between neighboring cells, causing their shapes and packing to become disordered in response to the mechanical stresses associated with lens growth and eye movements.
About the Journal of Cell Biology
Founded in 1955, the Journal of Cell Biology (JCB) is published by the Rockefeller University Press. All editorial decisions on manuscripts submitted are made by active scientists in conjunction with our in-house scientific editors. JCB content is posted to PubMed Central, where it is available to the public for free six months after publication. Authors retain copyright of their published works and third parties may reuse the content for non-commercial purposes under a creative commons license. For more information, please visit www.jcb.org.
Nowak, R.B., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200905065.
Rita Sullivan | EurekAlert!
Study identifies RNA molecule that shields breast cancer stem cells from immune system
23.05.2017 | Princeton University
“Pregnant” Housefly Males Demonstrate the Evolution of Sex Determination
23.05.2017 | Universität Zürich
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Earth Sciences
23.05.2017 | Life Sciences
23.05.2017 | Physics and Astronomy