How actin networks are actin'January 03, 2008Dynamic networks of growing actin filaments are critical for many cellular processes, including cell migration, intracellular transport, and the recovery of proteins from the cell surface. In this week's issue of the open-access journal PLoS Biology, researchers at Washington University in St. Louis shed light on how multiple proteins cooperate to regulate the assembly of such actin networks. A central player in generating actin networks is the Arp2/3 complex. In most cells, there are multiple proteins that can regulate the function of the Arp2/3 complex, although how the activities of these proteins are coordinated in the cell to generate the appropriate network of actin filaments in a complex, multi-step process remains unclear. To better understand how multiple Arp2/3 regulatory proteins are coordinated in the cell, Brian Galletta, Dennis Chuang, and John Cooper used a combination of live-cell imaging, computer-aided particle tracking, and quantitative motion analysis to determine how disruption of the function of each of these regulatory proteins, individually and its combination, altered the movement of actin patches in bakers yeast. These studies have revealed that while Arp2/3 regulatory proteins sometimes play overlapping roles in this process, they often play unique roles. The molecular machinery contained in actin patches can be found throughout nature. Therefore, Brian Galleta says that, "these studies should shed light on how actin networks are regulated in human cells during normal cell function and allow for a better understanding of how actin misregulation might contribute to the progression of disease processes including cancer, inflammation, and infection." Public Library of Science |
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| Related Actin Current Events and Actin News Articles How HIV cripples immune cells In order to be able to ward off disease pathogens, immune cells must be mobile and be able to establish contact with each other. The working group around Professor Dr. Oliver Fackler in the Virology Department of the Hygiene Institute of the Heidelberg University Hospital has discovered a mechanism in an animal model revealing how HIV, the AIDS pathogen, cripples immune cells: Cell mobility is inhibited by the HIV Nef protein. Study shows how disruption of spectrin-actin network causes lens cells in the eye to lose shape A network of proteins underlying the plasma membrane keeps epithelial cells in shape and maintains their orderly hexagonal packing in the mouse lens, say Nowak et al. Dividing cells 'feel' their way out of warp 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. UCF scientists control living cells with light; advances could enhance stem cells' power University of Central Florida researchers have shown for the first time that light energy can gently guide and change the orientation of living cells within lab cultures. St. Jude scientists discover a new mechanism controlling neuronal migration The molecular machinery that helps brain cells migrate to their correct place in the developing brain has been identified by scientists at St. Jude Children's Research Hospital. Building memories with actin Memories aren't made of actin filaments. But their assembly is crucial for long-term potentiation (LTP), an increase in synapse sensitivity that researchers think helps to lay down memories. Intestinal cells surprisingly active in pursuit of nutrition and defense Every cell lining the small intestine bristles with thousands of tightly packed microvilli that project into the gut lumen, forming a brush border that absorbs nutrients and protects the body from intestinal bacteria. Fate in fly sensory organ precursor cells could explain human immune disorder Notch signaling helps determine the fate of a number of different cell types in a variety of organisms, including humans. In an article that appears in the current issue of Nature Cell Biology, researchers at Baylor College of Medicine report that a new finding about the Notch signaling pathway in sensory organ precursor cells in the fruit fly could explain the mystery behind an immunological disorder called Wiskott-Aldrich syndrome. Advance in understanding cellulose synthesis Cellulose is a fibrous molecule that makes up plant cell walls, gives plants shape and form and is a target of renewable, plant-based biofuels research. Muscle atrophy through thick but not thin During desperate times, such as fasting, or muscle wasting that afflicts cancer or AIDS patients, the body cannibalizes itself, atrophying and breaking down skeletal muscle proteins to liberate amino acids. More Actin Current Events and Actin News Articles |
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