Two Kinesin Light Chain Genes in Mice
IDENTIFICATION AND CHARACTERIZATION OF THE ENCODED PROTEINS*
- From the ‡Howard Hughes Medical Institute, Division of Cellular and Molecular Medicine, Program in Biomedical Sciences and Department of Pharmacology, University of California San Diego, La Jolla, California 92093-0683 and the §Department of Pharmacology and Biochemistry, University of California, San Francisco, California 94143
Abstract
Native kinesin consists of two light chains and two heavy chains in a 1:1 stoichiometric ratio. To date, only one gene for kinesin light chain has been characterized, while a second gene was identified in a genomic sequencing study but not analyzed biochemically. Here we describe new genes encoding kinesin light chains in mouse. One of these light chains is neuronally enriched, while another shows ubiquitous expression. The presence of multiple kinesin light chain genes in mice is especially interesting, since there are two kinesin heavy chain genes in humans (Niclas, J., Navone, F., Hom-Booher, N., and Vale, R. D. (1994) Neuron 12, 1059–1072). To assess the selectivity of kinesin light chain interaction with the heavy chains, we performed immunoprecipitation experiments. The data suggested that the light chains form homodimers with no specificity in their interaction with the two heavy chains. Immunofluorescence and biochemical subfractionation suggested differences in the subcellular localization of the two kinesin light chain gene products. Although both kinesin light chains are distributed throughout the central and peripheral nervous systems, there is enrichment of one in sciatic nerve axons, while the other shows elevated levels in olfactory bulb glomeruli. These results indicate that the mammalian nervous system contains multiple kinesin light chain gene products with potentially distinct functions.
Footnotes
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↵* The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵¶ An investigator of the Howard Hughes Medical Institute. To whom correspondence should be addressed: HHMI/CMM Room 334, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0683. Tel.: 619-534-9702; Fax: 619-534-9701; E-mail:lgoldstein{at}ucsd.edu.
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↵1 The abbreviations used are: KHC, kinesin heavy chain(s); KLC, kinesin light chain(s); TPR, tetra-trico peptide repeats; GST, glutathione S-transferase; IF, immunofluorescence; PCR, polymerase chain reaction; bp, base pair(s); RIPA, radioimmune precipitation; PBS, phosphate-buffered saline; RACE, rapid amplification of cDNA ends; AMP-PNP, 5′-adenylyl-β,γ-imidodiphosphate; nKHC, neuronal kinesin heavy chain; uKHC, ubiquitous kinesin heavy chain.
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↵2 J. E. Lamerdin, personal communication.
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↵3 Available on the World Wide Web athttp://www.informatics.jax.org/encyclo.html.
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- Received January 8, 1998.
- Revision received April 2, 1998.
- The American Society for Biochemistry and Molecular Biology, Inc.
