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)

A microtubule-enriched fraction was prepared from bovine white matter, and kinesin and other microtubule-associated proteins were extracted from taxol-stabilized microtubules by homogenization and ultracentrifugation in the presence of nucleotides (guanosine triphosphate and adenosine triphosphate). The kinesin-enriched fractions were subjected to preparative SDS-PAGE, and the band representing the kinesin heavy chain was excised, homogenized, and subjected to partial enzymatic digestion with Staphylococcus aureus V8 protease. Four peptides were selected for sequence analysis and compared to the previously published sequence for the Drosophila kinesin heavy chain (Yang JT, Laymon RA, Goldstein LSB, Cell 56:879-889, 1989). All four peptides matched closely with portions of the Drosophila sequence corresponding to the central, alpha-helical domain. Total amino acid composition analysis of bovine kinesin heavy chain also reveals a high degree of homology to the Drosophila sequence.
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PMID:Kinesin heavy chain from bovine brain and Drosophila appear to be highly homologous molecules. 182 44

We report the cDNA sequence of the squid kinesin heavy chain and compared the predicted amino acid sequence with that of the Drosophila heavy chain as reported by Yang, J.T., Laymon, R.A., and Goldstein, L.S. B. (1989) Cell 56, 879-889). We compared the two kinesin sequences with regard to the predicted physicochemical parameters of hydrophobicity, charge, and propensities of the secondary conformations. A comparison of the sequences from the two species reveals the head, stalk, and tail domains because a reduced degree of conservation demarcates the stalk. The charge profile indicates that the head region is nearly neutral, the stalk region acidic, and the tail is basic. The Fourier transform analysis of the hydrophobic profile of the stalk shows predominant peaks at 1/3.5 and 1/2.3, which are indexed as the second and third orders of the period 7 residue. As in the Drosophila sequence, the rod domain is divided into an amino and a carboxyl subdomain by a predicted hinge region. We show that the disposition of hydrophobic residues is distinct in these two subdomains. In particular, the heptad repeat is more regular in the amino-terminal rod domain than in the carboxyl-terminal rod domain. The tail region is positively charged, a feature that is consistent with the known electrostatic interaction between the heavy chain and negatively charged surfaces such as glass coverslips and latex beads. Three monoclonal antibodies to the kinesin heavy chain have been mapped to a region within the carboxyl terminus of the stalk.
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PMID:The primary structure and analysis of the squid kinesin heavy chain. 213 56

We have studied single molecules and paracrystals of the stalk domain of the microtubule motor protein, kinesin, using circular dichroism, electron microscopy, and optical diffraction. The stalk is a rod-like particle, about 50 nm in length, with about 70% alpha-helical content (lower than tropomyosin and myosin). These data confirm the previous studies of M. De Cuevas, T. Tao, and L.S. B. Goldstein (J. Cell Biol. 116, 957-966, 1992). The particles also show a tendency to self-associate into dimers or higher aggregates, up to paracrystals with a periodic substructure. Four types of paracrystals have been observed, two with short periodicities (8 and 13 nm, types I and II) and two with periodicities comparable with the subunit length (53-63 nm, type III and 38 nm, type IV). Types I and II paracrystals can be interpreted to arise from a polar arrangement of subunits with alternating gaps and overlaps and different staggers between adjacent molecules. Type III and IV paracrystals appear to be formed from sets of antiparallel molecules, forming centrosymmetric patterns. The association properties may be important for functions of the kinesin stalk in microtubule-dependent motility.
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PMID:Paracrystalline structure of the stalk domain of the microtubule motor protein kinesin. 806 Jul 32

Conventional kinesin, kinesin-I, is a heterotetramer of two kinesin heavy chain (KHC) subunits (KIF5A, KIF5B, or KIF5C) and two kinesin light chain (KLC) subunits. While KHC contains the motor activity, the role of KLC remains unknown. It has been suggested that KLC is involved in either modulation of KHC activity or in cargo binding. Previously, we characterized KLC genes in mouse (Rahman, A., D.S. Friedman, and L.S. Goldstein. 1998. J. Biol. Chem. 273:15395-15403). Of the two characterized gene products, KLC1 was predominant in neuronal tissues, whereas KLC2 showed a more ubiquitous pattern of expression. To define the in vivo role of KLC, we generated KLC1 gene-targeted mice. Removal of functional KLC1 resulted in significantly smaller mutant mice that also exhibited pronounced motor disabilities. Biochemical analyses demonstrated that KLC1 mutant mice have a pool of KIF5A not associated with any known KLC subunit. Immunofluorescence studies of sensory and motor neuron cell bodies in KLC1 mutants revealed that KIF5A colocalized aberrantly with the peripheral cis-Golgi marker giantin in mutant cells. Striking changes and aberrant colocalization were also observed in the intracellular distribution of KIF5B and beta'-COP, a component of COP1 coatomer. Taken together, these data best support models that suggest that KLC1 is essential for proper KHC activation or targeting.
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PMID:Defective kinesin heavy chain behavior in mouse kinesin light chain mutants. 1049 91