Posts tagged cells
Articles and news from the latest research reports.
Protein Involved in DNA Replication, Centrosome Regulation Linked to Dwarfism, Small Brain Size
ScienceDaily (July 31, 2012) — Research just published by scientists at Cold Spring Harbor Laboratory (CSHL) links gene mutations found in some patients with Meier-Gorlin syndrome (MGS) with specific cellular dysfunctions that are thought to give rise to a particularly extreme version of dwarfism, small brain size, and other manifestations of abnormal growth which generally characterize that rare condition.
Although only 53 cases of Meier-Gorlin syndrome have been reported in the medical literature since the first patient was described in 1959, it is a malady whose mechanisms are bringing to light new functions for some of the cellular processes common to all life. Pathology related to MGS is traced in the new research to one of these, the fundamental process called mitosis in which cells replicate their genetic material and prepare to divide into two identical “daughter” cells.
CSHL President and Professor Bruce Stillman, Ph.D., a cancer biologist who has made seminal discoveries over three decades that have helped reveal the exquisite choreography of how chromosomes are duplicated in cells, led the new research, which suggests how, during mitosis, mutant versions of a protein called Orc1 contribute in two distinct ways to severe MGS pathology. The research is published online ahead of print in Genes & Development.
A: Fueling all this brain activity, and the basis for some imaging techniques, is a dense network of delicate blood vessels.
B: Neurons communicate with one another by releasing chemicals, such as dopamine, from pouches called vesicles. The vesicles, seen here in a fibroblast cell, have a geodesic outer coating that eventually pops through the side of the cell and releases its chemical message to be detected by the cell’s neighbors.
C: Our cells are surrounded by a scaffold of proteins that maintains a cell’s shape. Under an electron microscope, protein fibers called actin filaments look like braided ropes.
D: A few years ago, neuroscientists figured out how to take two fluorescent proteins that glowed in green or red and turn them into a rainbow of different colors that can be incorporated into individual neurons. Here the technique is used to stain cells in the cerebellum. The result? A “brainbow.”
Source: Portraits of the Mind: Visualizing the Brain from Antiquity to the 21st Century
To investigate membrane fusion during synaptic transmission (top), Rothman, Pincet, and colleagues designed an artificial version of the event. They exposed lipid nanodiscs embedded with SNARE proteins to vesicles containing complementary SNARE proteins. Only one SNARE protein complex was required for fusion between the discs and vesicles (A), but three were necessary to create a stable pore to release the neurotransmitter contained within the vesicle (B).