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Query: EC:3.6.4.4 (
kinesin
)
5,033
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Microtubules are important for organizing and directing many types of intracellular motility. Recently progress has been made in the analysis of two types of motility at the molecular level: the movement of
axonal
vesicles driven by
kinesin
, and the movement of chromosomes driven by the kinetochore. Both require ATP for movement in vitro. Kinesin-driven movement is unidirectional, towards the microtubule plus end, while movement of the kinetochore is bidirectional. These similarities and differences are discussed and incorporated into a new model for the kinetochore-microtubule interface.
...
PMID:The role of microtubule polarity in the movement of kinesin and kinetochores. 311 97
The
axonal
transport systems have a wide variety of primary roles and secondary responses in neurological disease processes. Recent advances in understanding these roles have built on the increasingly detailed insights into the cell biology of the axon and its supporting cells. Fast transport is a microtubule-based system of bidirectional movement of membranous organelles; the mechanism of translocation of these organelles involves novel proteins, including the recently described protein of fast anterograde transport,
kinesin
. Slow transport conveys the major cytoskeletal elements, microtubules, and neurofilaments. Several types of structural changes in diseased nerve fibers are understood in terms of underlying transport abnormalities. Altered slow transport of neurofilaments produces changes in
axonal
caliber (swelling or atrophy) and is involved in some types of perikaryal neurofibrillary abnormality. Secondary changes in slow
axonal
transport--for example, the reordered synthesis and delivery of cytoskeletal proteins after axotomy--also can produce changes in
axonal
caliber. Secondary demyelination can be a prominent late consequence of a sustained alteration of neurofilament transport. Impaired fast transport is found in experimental models of distal
axonal
degeneration (dying back). Retrograde
axonal
transport provides access to the central nervous system for agents such as polio virus and tetanus toxin, as well as access for known and hypothetical trophic factors. Correlative studies of
axonal
transport,
axonal
morphometry, cytoskeletal ultrastructure, and molecular biology of cytoskeletal proteins are providing extremely detailed reconstructions of the pathogenesis of experimental models of neurological disorders. A major challenge lies in the extension of these approaches to clinical studies.
...
PMID:Axonal transport in neurological disease. 327 71
Microtubules are involved in several forms of intracellular motility, including mitosis and organelle movement. Fast
axonal
transport is a highly ordered form of organelle motility that operates in both the anterograde (outwards from the cell body) and retrograde (from the periphery towards the cell body) direction. Similar microtubule-associated movement is observed in non-neuronal cells, and might be involved in secretion, endocytosis and the positioning of organelles within the cell. Kinesin is a mechanochemical protein that produces force along microtubules in an anterograde direction. We recently found that the brain microtubule-associated protein MAP 1C (ref. 7) is a microtubule-activated ATPase and, like
kinesin
, can translocate microtubules in an in vitro assay for microtubule-associated motility. MAP 1C seemed to be related to the ciliary and flagellar ATPase, dynein, which is thought to produce force in a direction opposite to that observed for
kinesin
. Here we report that MAP 1C, in fact, acts in a direction opposite to
kinesin
, and has the properties of a retrograde translocator.
...
PMID:Retrograde transport by the microtubule-associated protein MAP 1C. 367 Apr 2
New molecular motors associated with microtubules and actin have been uncovered very recently. Furthermore, studies of the mechanisms of bidirectional fast
axonal
transports have clarified new aspects of these processes, such as identification of a
kinesin
binding protein (kinectin) and regulation of
kinesin
dissociation from membranous organelles by phosphorylation. These will lead to a more precise understanding of the mechanisms of
axonal
transports. Concerning the mechanism of the slow transport of cytoskeletal proteins, new approaches have provided further evidence that the
axonal
cytoskeleton in mammalian systems is largely stationary while dynamic exchanges occur between polymer and a small pool of moving subunits.
...
PMID:Mechanism of axonal transport. Identification of new molecular motors and regulations of transports. 751 Aug 57
Neurons are highly polarized cells composed of dendrites, cell bodies, and long axons. Because of the lack of protein synthesis machinery in axons, materials required in axons and synapses have to be transported down the axons after synthesis in the cell body. Fast anterograde transport conveys different kinds of membranous organelles such as mitochondria and precursors of synaptic vesicles and
axonal
membranes, while organelles such as endosomes and autophagic prelysosomal organelles are conveyed retrogradely. Although
kinesin
and dynein have been identified as good candidates for microtubule-based anterograde and retrograde transporters, respectively, the existence of other motors for performing these complex
axonal
transports seems quite likely. Here we characterized a new member of the
kinesin
super-family, KIF3A (50-nm rod with globular head and tail), and found that it is localized in neurons, associated with membrane organelle fractions, and accumulates with anterogradely moving membrane organelles after ligation of peripheral nerves. Furthermore, native KIF3A (a complex of 80/85 KIF3A heavy chain and a 95-kD polypeptide) revealed microtubule gliding activity and baculovirus-expressed KIF3A heavy chain demonstrated microtubule plus end-directed (anterograde) motility in vitro. These findings strongly suggest that KIF3A is a new motor protein for the anterograde fast
axonal
transport.
...
PMID:KIF3A is a new microtubule-based anterograde motor in the nerve axon. 751 68
This paper describes the molecular and biochemical properties of KLP68D, a new
kinesin
-like motor protein in Drosophila melanogaster. Sequence analysis of a full-length cDNA encoding KLP68D demonstrates that this protein has a domain that shares significant sequence identity with the entire 340-amin acid kinesin heavy chain motor domain. Sequences extending beyond the motor domain predict a region of alpha-helical coiled-coil followed by a globular "tail" region; there is significant sequence similarity between the alpha-helical coiled-coil region of the KLP68D protein and similar regions of the KIF3 protein of mouse and the KRP85 protein of sea urchin. This finding suggests that all three proteins may be members of the same family, and that they all perform related functions. KLP68D protein produced in Escherichia coli is, like
kinesin
itself, a plus-end directed microtubule motor. In situ hybridization analysis of KLP68D RNA in Drosophila embryos indicates that the KLP68D gene is expressed primarily in the central nervous system and in a subset of the peripheral nervous system during embryogenesis. Thus, KLP68D may be used for anterograde
axonal
transport and could conceivably move cargoes in fly neurons different than those moved by kinesin heavy chain or other plus-end directed motors.
...
PMID:Characterization of the KLP68D kinesin-like protein in Drosophila: possible roles in axonal transport. 752
Two microtubule-stimulated ATPases, cytoplasmic dynein, and
kinesin
, are believed to be responsible for the intracellular movement of membrane-bound organelles in opposite directions along microtubules. An unresolved component of this model is the mechanism by which cells regulate these two motors to direct various membrane-bound organelles to their proper locations. To determine if phosphorylation may play a role in the regulation of cytoplasmic dynein, the in vivo phosphorylation state of cytoplasmic dynein from two cellular pools was examined. The entire cellular pool of brain cytoplasmic dynein was metabolically labeled by the infusion of [32P]orthophosphate into the cerebrospinal fluid of rat brain ventricles. To characterize the phosphorylation of dynein associated with anterograde membrane-bound organelles, the optic nerve fast
axonal
transport system was used. Using a monoclonal antibody to the 74-kD polypeptide of brain cytoplasmic dynein, the native dynein complex was immunoprecipitated from the radiolabled tissue extracts. Autoradiographs of one and two dimensional gels showed labeling of nearly all of the polypeptide isoforms of cytoplasmic dynein from rat brain. These polypeptides are phosphorylated on serine residues. Comparison of the amount of 32P incorporated into the dynein polypeptides revealed differences in the phosphorylation of dynein polypeptides from the anterograde and the cellular pools. Most interestingly, the 530-kD heavy chain of dynein appears to be phosphorylated to a lesser extent in the anterograde pool than in the cellular pool. Since the anterograde pool contains inactive dynein, while the entire cellular pool contains both inactive and active dynein, these results are consistent with the hypothesis that phosphorylation regulates the functional activity of cytoplasmic dynein.
...
PMID:Differential phosphorylation in vivo of cytoplasmic dynein associated with anterogradely moving organelles. 752 20
Clathrin, which constitutes coated vesicles and plays important roles in neuronal functions, has been reported to be involved in the pathology of Alzheimer's disease. In the brains of the patients with Pick's disease, distribution of clathrin was immunohistochemically investigated using monoclonal antibodies binding to different epitopes of clathrin light chain a and b. All the antibodies intensely labeled Pick's body and some perikarya of neurons, indicating impairment of slow
axonal
transport b (SCb). Antibodies against neurofilament,
kinesin
and synaptophysin also labeled Pick's body. These observations suggested impairment of
axonal
transport in the brains with Pick's disease, and might contribute to elucidating the pathology of Pick's body forming. It is implied that common pathological processes might lie in Alzheimer's disease and Pick's disease.
...
PMID:Involvement of clathrin light chains in the pathology of Pick's disease; implication for impairment of axonal transport. 753 77
Kinesin is known as a representative cytoskeletal motor protein that is engaged in cell division and
axonal
transport. In addition to the mutant assay, recent advances using the PCR cloning technique have elucidated the existence of many kinds of
kinesin
-related proteins in yeast, Drosophila, and mice. We previously cloned five different members of
kinesin
superfamily proteins (KIFs) in mouse brain (Aizawa, H., Y. Sekine, R. Takemura, Z. Zhang, M. Nangaku, and N. Hirokawa. 1992. J. Cell Biol. 119:1287-1296) and demonstrated that one of them, KIF3A, is an anterograde motor (Kondo, S., R. Sato-Yashitake, Y. Noda, H. Aizawa, T. Nakata, Y. Matsuura, and N. Hirokawa. J. Cell Biol. 1994. 125:1095-1107). We have now characterized another
axonal
transport motor, KIF2. Different from other KIFs, KIF2 is a central type motor, since its motor domain is located in the center of the molecule. Recombinant KIF2 exists as a dimer with a bigger head and plus-end directionally moves microtubules at a velocity of 0.47 +/- 0.11 microns/s, which is two thirds that of
kinesin
's. Immunocytological examination showed that native KIF2 is abundant in developing axons and that it accumulates in the proximal region of the ligated nerves after a 20-h ligation. Soluble KIF2 exists without a light chain, and KIF2's associated-vesicles, immunoprecipitated by anti-KIF2 antibody, are different from those carried by existing motors such as
kinesin
and KIF3A. They are also distinct from synaptic vesicles, although KIF2 is accumulated in so-called synaptic vesicle fractions and embryonal growth cone particles. Our results strongly suggest that KIF2 functions as a new anterograde motor, being specialized for a particular group of membranous organelles involved in fast
axonal
transport.
...
PMID:KIF2 is a new microtubule-based anterograde motor that transports membranous organelles distinct from those carried by kinesin heavy chain or KIF3A/B. 753 3
We have previously demonstrated that the in vivo vitreal injection of an antisense oligonucleotide directed to the kinesin heavy chain inhibits retinal
kinesin
synthesis by 82% and concomitantly inhibits rapid transport of total protein into the optic nerve by 70%. These results establish a major role for
kinesin
in rapid
axonal
transport in vivo. Recently, the cloning of a family of
kinesin
-like molecules from the mammalian brain has been reported, and some of these proteins are also expressed in neurons. To assign to specific function to the kinesin heavy chain we inhibited the
kinesin
synthesis with an antisense
kinesin
oligonucleotide and assessed the
axonal
transport into the optic nerve of representative proteins from each of three vesicle classes that contain rapidly transported proteins. Marker proteins used were substance P for peptide-containing synaptic vesicles, the amyloid protein for plasma membrane precursor vesicles, and several integral synaptic vesicle proteins. Our results indicate that the major anterograde motor protein for all three vesicle classes utilizes kinesin heavy chain, although we discuss alternative explanations.
...
PMID:Inhibition of kinesin synthesis in vivo inhibits the rapid transport of representative proteins for three transport vesicle classes into the axon. 753 13
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