KINESIN BYPASSING BLOCKAGES ON MICROTUBULE RAILS

2009 ◽  
Vol 04 (01n02) ◽  
pp. 139-151 ◽  
Author(s):  
KERSTIN DREBLOW ◽  
NIKOLINA KALCHISHKOVA ◽  
KONRAD J. BÖHM
Keyword(s):  
Axonal Transport ◽  
Motor Neurons ◽  
Experimental Approach ◽  
Mechanical Energy ◽  
Fast Axonal Transport ◽  
Effective Mechanism ◽  
Tubulin Dimer ◽  
Cargo Transport ◽  
Kinesin Molecule ◽  
Conventional Kinesin

Kinesins are motor proteins which convert the chemical energy of ATP into mechanical energy to move along proteinaceous microtubule rails and to transport different cargoes to defined intracellular destinations. It is well documented that following the track of a single protofilament is the thermodynamically most effective mechanism of kinesin movement along microtubules. However, the question arises what happens when a kinesin molecule encounters a hindrance along the protofilament. The present study describes a simple, cell-free approach which enables to study the effects of structural blockages on kinesin-based transport. This experimental approach uses dimeric conventional kinesin moving nanometre-sized gold beads along immobilized microtubules whose surface has been irreversibly decorated by blocking proteins. We demonstrated that the continuous bead transport temporarily stopped at sites of blockages, but usually continued after a certain resting time. Our results suggest that single dimeric kinesin molecules are able to change to another protofilament if the next tubulin dimer where the second head should bind is blocked. A bypassing mechanism is discussed which is considered to be one fundamental prerequisite to realize a kinesin-mediated cargo-transport along microtubules over long distances, required for e.g., the fast axonal transport in motor neurons.

scholarly journals Cytoplasmic Dynein, the Dynactin Complex, and Kinesin Are Interdependent and Essential for Fast Axonal Transport

1999 ◽  
Vol 10 (11) ◽  
pp. 3717-3728 ◽  
Author(s):  
MaryAnn Martin ◽  
Stanley J. Iyadurai ◽  
Andrew Gassman ◽  
Joseph G. Gindhart ◽  
Thomas S. Hays ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Heavy Chain ◽  
Cytoplasmic Dynein ◽  
Genetic Interactions ◽  
Organelle Transport ◽  
Fast Axonal Transport ◽  
Anterograde Transport ◽  
Dynein Heavy Chain ◽  
Conventional Kinesin ◽  
Dynactin Complex

In axons, organelles move away from (anterograde) and toward (retrograde) the cell body along microtubules. Previous studies have provided compelling evidence that conventional kinesin is a major motor for anterograde fast axonal transport. It is reasonable to expect that cytoplasmic dynein is a fast retrograde motor, but relatively few tests of dynein function have been reported with neurons of intact organisms. In extruded axoplasm, antibody disruption of kinesin or the dynactin complex (a dynein activator) inhibits both retrograde and anterograde transport. We have tested the functions of the cytoplasmic dynein heavy chain (cDhc64C) and the p150Glued(Glued) component of the dynactin complex with the use of genetic techniques in Drosophila.cDhc64C and Glued mutations disrupt fast organelle transport in both directions. The mutant phenotypes, larval posterior paralysis and axonal swellings filled with retrograde and anterograde cargoes, were similar to those caused by kinesin mutations. Why do specific disruptions of unidirectional motor systems cause bidirectional defects? Direct protein interactions of kinesin with dynein heavy chain and p150Glued were not detected. However, strong dominant genetic interactions between kinesin, dynein, and dynactin complex mutations in axonal transport were observed. The genetic interactions between kinesin and either Glued orcDhc64C mutations were stronger than those betweenGlued and cDhc64C mutations themselves. The shared bidirectional disruption phenotypes and the dominant genetic interactions demonstrate that cytoplasmic dynein, the dynactin complex, and conventional kinesin are interdependent in fast axonal transport.

Differential Screening of Mutated SOD1 Transgenic Mice Reveals Early Up-Regulation of a Fast Axonal Transport Component in Spinal Cord Motor Neurons

2000 ◽  
Vol 7 (4) ◽  
pp. 274-285 ◽  
Author(s):  
Luc Dupuis ◽  
Marc de Tapia ◽  
Frédérique René ◽  
Bernadette Lutz-Bucher ◽  
Jon W. Gordon ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Transgenic Mice ◽  
Axonal Transport ◽  
Motor Neurons ◽  
Differential Screening ◽  
Fast Axonal Transport ◽  
Transport Component

scholarly journals Immunochemical analysis of kinesin light chain function.

1997 ◽  
Vol 8 (4) ◽  
pp. 675-689 ◽  
Author(s):  
D L Stenoien ◽  
S T Brady
Keyword(s):  
Axonal Transport ◽  
Light Chain ◽  
Membrane Vesicles ◽  
Retrograde Transport ◽  
Light Chains ◽  
Fast Axonal Transport ◽  
Kinesin Light Chain ◽  
Punctate Pattern ◽  
Conventional Kinesin

The kinesin heterotetramer consists of two heavy and two light chains. Kinesin light chains have been proposed to act in binding motor protein to cargo, but evidence for this has been indirect. A library of monoclonal antibodies directed against conserved epitopes throughout the kinesin light chain sequence were used to map light chain functional architecture and to assess physiological functions of these domains. Immunocytochemistry with all antibodies showed a punctate pattern that was detergent soluble. A monoclonal antibody (KLC-All) made against a highly conserved epitope in the tandem repeat domain of light chains inhibited fast axonal transport in isolated axoplasm by decreasing both the number and velocity of vesicles moving, whereas an antibody against a conserved amino terminus epitope had no effect. KLC-All was equally effective at inhibiting both anterograde and retrograde transport. Neither antibody inhibited microtubule-binding or ATPase activity in vitro. KLC-All was unique among antibodies tested in releasing kinesin from purified membrane vesicles, suggesting a mechanism of action for inhibition of axonal transport. These results provide further evidence that conventional kinesin is a motor for fast axonal transport and demonstrate that kinesin light chains play an important role in kinesin interaction with membranes.

scholarly journals C9orf72-derived arginine-containing dipeptide repeats associate with axonal transport machinery and impede microtubule-based motility

2021 ◽  
Vol 7 (15) ◽  
pp. eabg3013
Author(s):  
Laura Fumagalli ◽  
Florence L. Young ◽  
Steven Boeynaems ◽  
Mathias De Decker ◽  
Arpan R. Mehta ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Motor Neurons ◽  
Single Molecule ◽  
Repeat Expansion ◽  
Physical Interaction ◽  
Hexanucleotide Repeat ◽  
Hexanucleotide Repeat Expansion ◽  
Axonal Trafficking ◽  
Inhibitory Interactions

A hexanucleotide repeat expansion in the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). How this mutation leads to these neurodegenerative diseases remains unclear. Here, we show using patient stem cell–derived motor neurons that the repeat expansion impairs microtubule-based transport, a process critical for neuronal survival. Cargo transport defects are recapitulated by treating neurons from healthy individuals with proline-arginine and glycine-arginine dipeptide repeats (DPRs) produced from the repeat expansion. Both arginine-rich DPRs similarly inhibit axonal trafficking in adult Drosophila neurons in vivo. Physical interaction studies demonstrate that arginine-rich DPRs associate with motor complexes and the unstructured tubulin tails of microtubules. Single-molecule imaging reveals that microtubule-bound arginine-rich DPRs directly impede translocation of purified dynein and kinesin-1 motor complexes. Collectively, our study implicates inhibitory interactions of arginine-rich DPRs with axonal transport machinery in C9orf72-associated ALS/FTD and thereby points to potential therapeutic strategies.

scholarly journals Kinesin Mutations Cause Motor Neuron Disease Phenotypes by Disrupting Fast Axonal Transport in Drosophila

Genetics ◽  
1996 ◽  
Vol 144 (3) ◽  
pp. 1075-1085 ◽  
Author(s):  
Daryl D Hurd ◽  
William M Saxton
Keyword(s):  
Motor Neuron ◽  
Axonal Transport ◽  
Action Potentials ◽  
Light And Electron Microscopy ◽  
Synaptic Membrane ◽  
Slow Axonal Transport ◽  
Fast Axonal Transport ◽  
Motor Neuron Diseases ◽  
Transmitter Secretion ◽  
Axon Terminals

Abstract Previous work has shown that mutation of the gene that encodes the microtubule motor subunit kinesin heavy chain (Khc) in Drosophila inhibits neuronal sodium channel activity, action potentials and neurotransmitter secretion. These physiological defects cause progressive distal paralysis in larvae. To identify the cellular defects that cause these phenotypes, larval nerves were studied by light and electron microscopy. The axons of Khc mutants develop dramatic focal swellings along their lengths. The swellings are packed with fast axonal transport cargoes including vesicles, synaptic membrane proteins, mitochondria and prelysosomal organelles, but not with slow axonal transport cargoes such as cytoskeletal elements. Khc mutations also impair the development of larval motor axon terminals, causing dystrophic morphology and marked reductions in synaptic bouton numbers. These observations suggest that as the concentration of maternally provided wild-type KHC decreases, axonal organelles transported by kinesin periodically stall. This causes organelle jams that disrupt retrograde as well as anterograde fast axonal transport, leading to defective action potentials, dystrophic terminals, reduced transmitter secretion and progressive distal paralysis. These phenotypes parallel the pathologies of some vertebrate motor neuron diseases, including some forms of amyotrophic lateral sclerosis (ALS), and suggest that impaired fast axonal transport is a key element in those diseases.

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