Not exact matches
The axoneme's movement is accomplished via rows of motor
proteins called dyneins that are attached
along the
microtubules and exert force on them so the
microtubules «slide» past each other, which then causes the entire axoneme and sperm tail to bend and move.
A group of LMU physicists led by Professor Erwin Frey, in collaboration with Professor Stefan Diez (Technical University of Dresden and Max Planck Institute for Molecular Cell Biology and Genetics, Dresden), has now developed a model in which the motor
proteins that are responsible for the transport of cargo
along protofilaments also serve to regulate
microtubule lengths.
The team found changes in a gene encoding a previously unknown «dynein,» a
protein that moves like a railroad locomotive
along cytoskeletal fibers called
microtubules, hauling other molecules as cargo.
Building from two subunits, alpha and beta tubulin, this
protein assembles into
microtubules that play a vital role inside cells — giving structure, pushing or pulling other things around, or providing a track on which other molecules can pull themselves
along.
When the researchers administered drugs to inhibit the movement of certain «motor»
proteins that transport mitochondria and other cargo within the cell by traveling
along microtubules, the mitochondria accumulated in the axon of the neuron and never made it to the synaptic terminal.
This dimer gives
microtubules directionality, which is key to many of their other properties, such as being able to assemble or disassemble from either end, and allowing motor
proteins to walk
along them in a specific direction.
The study, published on October 6 in Cell, describes how two
proteins work together to guide the growth of a new
microtubule along an existing one.
Experiments also revealed that as pairs of
microtubules were jiggled, these
proteins shuffled
along them in the direction of least resistance, toward either the plus or minus end of the
microtubules.
Motor
proteins carry cargoes
along microtubules in cells.
Proteins travel from one end of a neuron to the other by moving
along microtubules.
Motor
proteins powered by adenosine triphosphate, which supplies chemical energy, «walk»
along microtubules to deliver cargo throughout cells and discard trash.
His group's paper in the Journal of Physics A: Mathematical and Theoretical describes a new theoretical approach to study the effect of intermolecular interactions on the dynamics of motor
proteins that move
along cytoskeletal filaments known as
microtubules.
In fact, the researchers were surprised to find that weak repulsions led to maximum movement
along the
microtubules and that motor
proteins are more sensitive to attraction rather than repulsion.
In research detailed last week in Cell, the Rockefeller team discovered some of these fastener
proteins, known as non-motor
microtubule associated
proteins, or MAPs, experience different degrees of friction depending on the direction in which they are being moved
along a
microtubule.
Miniscule carriers, the motor
proteins, slide
along the
microtubules with great volumes such as chromosomes, vesicles and other subcellular components — like mitochondria — latched onto them.
The «parts list» in these processes is similar:
Microtubules, semi-rigid tubes of protein, can serve within the cell as scaffolding, roadways, and a building material for machinery; some proteins serve as fasteners, binding and releasing other materials; and motor proteins use chemical energy to push and pull materials along microtubules, or move the microtubules
Microtubules, semi-rigid tubes of
protein, can serve within the cell as scaffolding, roadways, and a building material for machinery; some
proteins serve as fasteners, binding and releasing other materials; and motor
proteins use chemical energy to push and pull materials
along microtubules, or move the microtubules
microtubules, or move the
microtubulesmicrotubules themselves.
Motor
proteins carry cargoes
along microtubules in cells as seen in this image from an earlier study at Rice.