Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

The present paper describes two new monoclonal antibodies (MAbs) KN-02 and KN-03 against the heavy chain of conventional kinesin. The kinesin was purified from porcine brain by a combined procedure of ion exchange chromatography, tripolyphosphate-supported microtubule affinity-binding, and gel filtration. Hybridoma cell lines producing antibodies were obtained after immunization of a Balb/c mouse with kinesin and subsequent fusion of the spleen cells with Sp2/0 myeloma cells. The specificity was verified by enzyme-linked immunosorbent assay (ELISA) and further confirmed by immunoblotting and immunoprecipitation analysis. The antibodies recognize different epitopes on the heavy chain of the kinesin molecule as demonstrated by chymotryptic cleavage of kinesin followed by immunoblotting. Differential location of relevant epitopes was also documented by in vitro binding experiments with purified kinesin and taxol-stabilized microtubules. While the KN-03 antibody decorated microtubules, no such staining was observed with KN-02 antibody. The antibodies have a lower affinity to sodium dodecyl sulfate (SDS)-denatured kinesin, but immunofluorescence on fixed cells gave strong dot-like staining characteristic for localization of kinesin on vesicles. The same staining pattern was observed in different cell types. Double-label fluorescence with polyclonal anti-tubulin antibody revealed a co-distribution of stained vesicles with microtubules on the cell periphery. The antibodies KN-02 and KN-03 are therefore valuable tools for localization of kinesins in cells of different tissue origin.
Hybrid Hybridomics 2002 Dec
PMID:Monoclonal antibodies KN-02 and KN-03 against the heavy chain of kinesin. 1257 9

Aurora kinases representing a novel family of serine/threonine kinases have been identified as key regulators of the mitotic cell division process. The three members of this kinase family, identified so far, referred to as Aurora-A, Aurora-B and Aurora-C kinases, are close homologues of the prototypic yeast Ipll and Drosophila aurora kinases, which are known to be involved in the regulation of centrosome function, bipolar spindle assembly and chromosome segregation processes. All three members of the mammalian kinase family have a catalytic domain that is highly conserved with a short C-terminal domain and an N-terminal domain of varying sizes. Following their discovery about five years ago, extensive research has focused on understanding the biological roles of these kinases and elucidation of their pathways, which regulate cell proliferation and maintenance of normal cellular phenotypes. Significant interest in the subject was generated since all three Aurora kinases family members were reported to be overexpressed in many human cancers, and elevated expression has been correlated with chromosomal instability and clinically aggressive disease in some instances. Ectopic overexpression of one member of the family, Aurora-A, was shown to induce oncogenic transformation in cells. Unlike most other putative oncogenes identified, so far, members of this kinase family are expressed and active at the highest level during G2-M phase of the cell cycle. Aurora kinases are localized at the centrosomes of interphase cells, at the poles of the bipolar spindle and in the midbody of the mitotic apparatus. Substrates identified for the Aurora-A and Aurora-B kinases, include a kinesin-like motor protein, spindle apparatus proteins, histone H3 protein, kinetochore protein and the tumor suppressor protein p53. Identification of Aurora kinases as RasGAP Src homology 3 domain binding protein, also implicates these kinases as potential effectors in the Ras pathway relevant to oncogenesis. Abnormal elevated expression of Aurora kinases detected in human cancer cells could help explain the underlying biological mechanisms responsible for the development of many cellular phenotypes associated with malignant cells. Identification of these mechanisms offers the possibility of designing novel targeted therapies for cancer in the future.
Cancer Metastasis Rev 2003 Dec
PMID:The Aurora kinases: role in cell transformation and tumorigenesis. 1288 18

The kinesin family member BimC has a highly positively charged domain of approximately 70 amino acids at the N terminus of the motor domain. Motor domain constructs of BimC were prepared with and without this extra domain to determine its influence. The level of microtubules needed for half saturation of the ATPase of BimC motor domain constructs is reduced by approximately 7000-fold at low ionic strength upon addition of this extra N-terminal extension. Although the change in microtubule affinity is less at higher salt, addition of the N-terminal domain still produces a 20-fold increase in affinity for microtubules in 200 mm potassium acetate. A fusion protein of the N-terminal domain and thioredoxin binds tightly to MTs at low salt, consistent with the increased affinity of motor domain constructs (which contain the N-terminal domain) being due to the additional binding of the N-terminal domain to the microtubule. Hydrodynamic analysis indicates that the N-terminal extension is in a highly extended conformation, suggesting that it may be intrinsically disordered. Fusion of the N-terminal extension of BimC onto the motor domain of conventional kinesin produces a similar large increase in microtubule affinity without significant reduction in kcat or velocity in an in vitro motility assay, suggesting that the N-terminal extension can act in a modular manner to increase the microtubule affinity of kinesin motor domains without a decrease in velocity.
J Biol Chem 2003 Dec 26
PMID:The kinesin family member BimC contains a second microtubule binding region attached to the N terminus of the motor domain. 1453 Feb 65

Beta-dystrobrevin, a member of the dystrobrevin protein family, is a dystrophin-related and -associated protein restricted to non-muscle tissues and is highly expressed in kidney, liver and brain. Dystrobrevins are now thought to play an important role in intracellular signal transduction, in addition to providing a membrane scaffold in muscle, but the precise role of beta-dystrobrevin has not yet been determined. To study beta-dystrobrevin's function in brain, we used the yeast two-hybrid approach to look for interacting proteins. Four overlapping clones were identified that encoded Kif5A, a neuronal member of the Kif5 family of proteins that consists of the heavy chains of conventional kinesin. A direct interaction of beta-dystrobrevin with Kif5A was confirmed by in vitro and in vivo association assays. Co-immunoprecipitation with a monoclonal kinesin heavy chain antibody precipitated both alpha- and beta-dystrobrevin, indicating that this interaction is not restricted to the beta-dystrobrevin isoform. The site for Kif5A binding to beta-dystrobrevin was localized in a carboxyl-terminal region that seems to be important in heavy chain-mediated kinesin interactions and is highly homologous in all three Kif5 isoforms, Kif5A, Kif5B and Kif5C. Pull-down and immunofluorescence experiments also showed a direct interaction between beta-dystrobrevin and Kif5B. Our findings suggest a novel function for dystrobrevin as a motor protein receptor that might play a major role in the transport of components of the dystrophin-associated protein complex to specific sites in the cell.
J Cell Sci 2003 Dec 01
PMID:Beta-dystrobrevin interacts directly with kinesin heavy chain in brain. 1460 Feb 69

Human PPFIA1 (also known as LIP.1 or Liprin alpha1) gene, located within CCND1-FGF4-EMS1 amplicon at human chromosome 11q13.3, encodes KIF1A-binding protein, which is implicated in trafficking of LAR subfamily PTPases and AMPA-type glutamate receptors. Human PPFIA4 (AF034801) and rat Ppfia4 (AY057064) are 5'-truncated partial cDNAs, and the complete coding sequence of PPFIA4 ortholog of any species remained to be identified. Here, we determined the complete coding sequence of human PPFIA4 gene by using bioinformatics. Exons 1-12 of PPFIA4 gene were located within human genome sequence AC096632.3, while exons 11-29 within AL451082.6. PPFIA4-MYOG locus (human chromosome 1q32.1) was paralogous to PPFIA2-LIN7A-MYF5-MYF6 locus (12q21.31), which was also paralogous to PPFIA3-LIN7B locus (19q13.41). PPFIA4 (1186 aa) showed 70.9%, 67.1%, and 61.8% total-amino-acid identity with PPFIA2, PPFIA1, and PPFIA3, respectively. PPFIA family members consist of PFIH1, PFIH2, PFIH3, PFIH4 domains and three SAM (Sterile alpha motif) domains. C-terminal binding domain for GRIP proteins (VRTYSC motif) was present in PPFIA1, PPFIA2 and PPFIA3, but not in PPFIA4. Bipartite nuclear localization signal was included within PFIH4 domain. PFIH2 domain was identical to ERM or Smc domain. The region spanning PFIH2-PFIH3 domains is the binding domain for KIF1A. The region spanning SAM1-SAM3 domains is the binding domain for LAR subfamily PTPases and PPFIBP (Liprin beta) family proteins. This is the first report on comprehensive characterization of PPFIA4 belonging to the PPFIA family of kinesin-cargo linkers.
Int J Mol Med 2003 Dec
PMID:Identification and characterization of human PPFIA4 gene in silico. 1461 82

In the post-Genome era, new concepts emerge about the growth regulation of uterine leiomyomata. Screening of leiomyoma and myometrial tissues with DNA arrays revealed numerous genes up-regulated in leiomyomata that were not known to be expressed in the human uterus. GluR2, a subunit of a ligand-gated cation channel, is up-regulated in leiomyomata relative to myometrium by 15- to 30-fold at the protein and mRNA level and is localized in endothelial cells. GluR2 pre-mRNA in leiomyoma and myometrial tissues is nearly 100% edited at the Q/R site, indicative of low Ca(2+) permeability of the ion channels. In spontaneous leiomyomata in women or leiomyomata induced in the guinea pig model, there is a likely synergism linking increased production of estradiol and all-trans retinoic acid with up-regulation of nuclear receptor PPARgamma and RXRalpha proteins to support tumor growth. GluR2 might be coupled to this synergism directly or via interleukin-17B, kinesin KIF5 or related genes also up-regulated in leiomyomata. GluR antagonists should be tested as inhibitors of leiomyoma growth.
Biochem Biophys Res Commun 2003 Dec 05
PMID:New potential regulators of uterine leiomyomata from DNA arrays: the ionotropic glutamate receptor GluR2. 1463 51

Axonal transport is the specialized and well-developed intracellular transport system for regulated and/or long-distance transport based on generalized cellular machineries. Among them, slow axonal transport conveys cytoplasmic proteins. The motor molecule, the nature of transporting complex and the transport regulation mechanism for slow transport are still unclarified. There has been a dispute regarding the nature of transporting complex of cytoskeletal proteins, polymer-sliding hypothesis versus subunit-transport theory. Recent data supporting the hypothesis of polymer sliding in cultured neurons only reconfirm the previously reported structure and this inference suffers from the lack of ultrastructural evidence and the direct relevance to the physiological slow transport phenomenon in vivo. Observation of the moving cytoskeletal proteins in vivo using transgenic mice or squid giant axons revealed that subunits do move in a microtubule-dependent manner, strongly indicating the involvement of microtubule-based motor kinesin. If the slow transport rate reflects the intermittent fast transport dependent on kinesin motor, we have to investigate the molecular constituents of the transporting complex in more detail and evaluate why the motor and cargo interaction is so unstable. This kind of weak and fluctuating interaction between various molecular pairs could not be detected by conventional techniques, thus necessitating the establishment of a new experimental system before approaching the molecular regulation problem.
Neurosci Res 2003 Dec
PMID:Where does slow axonal transport go? 1463 Mar 40

A conventional kinesin molecule travels continuously along a microtubule in discrete 8-nm steps. This processive movement is generally explained by models in which the two identical heads of a kinesin move in a 'hand-over-hand' manner. Here, we show that a single heterodimeric kinesin molecule (in which one of the two heads is mutated in a nucleotide-binding site) exhibits fast and slow (with the dwell time at least 10 times longer than that of the fast step) 8-nm steps alternately, presumably corresponding to the displacement by the wild-type and mutant heads, respectively. Our results provide the first direct evidence for models in which the roles of the two heads alternate every 8-nm step.
Nat Cell Biol 2003 Dec
PMID:Alternate fast and slow stepping of a heterodimeric kinesin molecule. 1464 99

Molecular motor proteins, fueled by energy from ATP hydrolysis, move along actin filaments or microtubules, performing work in the cell. The kinesin microtubule motors transport vesicles or organelles, assemble bipolar spindles or depolymerize microtubules, functioning in basic cellular processes. The mechanism by which motor proteins convert energy from ATP hydrolysis into work is likely to differ in basic ways from man-made machines. Several mechanical elements of the kinesin motors have now been tentatively identified, permitting researchers to begin to decipher the mechanism of motor function. The force-producing conformational changes of the motor and the means by which they are amplified are probably different for the plus- and minus-end kinesin motors.
Bioessays 2003 Dec
PMID:Kinesin motors as molecular machines. 1463 56

Cell multiplication requires sequestration of the duplicated and segregated genome into two daughter cells. The mitotic spindle is critical for orchestrating sister chromatid separation and division plane positioning. During anaphase, spindle microtubules become bundled to form the central spindle, which is essential for completion of cytokinesis. Central spindle assembly is mediated by a microtubule-associated protein and a kinesin-RhoGAP complex, both of which are regulated by phosphorylation/dephosphorylation. The central spindle also plays a role in cleavage furrow positioning, which appears to involve activation of RhoA. New results have provided some initial clues as to how furrow positioning is achieved. Particularly notable is the discovery that a protein activated by RhoA, formin, has actin nucleation activity.
Curr Opin Cell Biol 2003 Dec
PMID:Cytokinesis: progress on all fronts. 1464 92


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