“There’s no little man sitting there, putting the protein in the right place,” said Don Arnold, a molecular and computational biologist at USC College.
“Proteins have to have in them encoded information that tells them where to go in the cell.”
In a study appearing online this week in Nature Neuroscience, Arnold and collaborators solve the mystery for key proteins in the brain.
Neurons have separate structures for receiving signals (dendrites) and for sending them (axons). The electrical properties of each depend on different proteins. But the proteins travel in bubbles, or vesicles, powered by motors known as kinesins that travel along tiny molecular paths.
Even though the paths point to both axons and dendrites, dendritic proteins end up in dendrites, and axonal proteins go to the axons. How?
Arnold’s group discovered a crude but effective sorting mechanism. At first, kinesins blindly carry both types of proteins towards the axon.
However, dendritic proteins enable the vesicles transporting them to bind to a second motor, known as myosin, that literally walks them back into the dendrite.
This filter ensures that only axonal proteins make it into the axon. The others are caught by the second motor and diverted to the dendrite.
“This mechanism fishes these things out of the axon,” Arnold said.
Once in the dendrite, the proteins either land in a place where they can do their electrical work or they move back towards the axon, only to be fished out again.
On its face, the process is inefficient, Arnold said, “but it is very effective.”
The discovery may enable finer control over neurons for basic research or for treatment of neurological disorders. Potentially, scientists could target only dendrites or axons in a neuron so as to study its outgoing or incoming impulses.
In addition to these potential applications, the study is notable for its contribution to the understanding of the brain and of protein transport in general.
“It’s a very basic question, something people have been wondering about for a long time,” Arnold said.
The co-authors on the study were first author Tommy Lewis, a graduate student in the molecular and computational biology graduate program at USC, as well as Tianyi Mao and Karel Svoboda from the Howard Hughes Medical Institute at the Janelia Farm Research Campus.
The National Institutes of Health and the Howard Hughes Medical Institute funded the research.
Carl Marziali | EurekAlert!
Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute
'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Materials Sciences
27.10.2016 | Physics and Astronomy
27.10.2016 | Life Sciences