The Cloning and Analysis of LEK1 Identifies Variations in the LEK/Centromere Protein F/Mitosin Gene Family*
Abstract
We report the cloning of a novel murine cDNA, LEK1, that is related to human CENP-F and mitosin and more distantly to chicken CMF1. The proteins from these three organisms have significant homology, yet differ in their temporal, spatial, and subcellular localizations. The human proteins bind the kinetochore in mitotic cells, whereas the chicken protein is found only in skeletal and cardiac muscle and is developmentally regulated. Mouse LEK1 is a single copy gene that codes for two developmentally regulated transcripts. The LEK1 protein is expressed early and ubiquitously in mouse development and is generally down-regulated as development proceeds in a manner that correlates to a cessation of mitosis. In adult tissues, the LEK1 protein is detected exclusively in the pronucleus of the oocyte and was not observed in other actively dividing tissues. Subcellular localization revealed that the LEK1 protein in mitotic cells does not bind the kinetochore. From these data, we hypothesize that chicken CMF1, human CENP-F, mitosin, and mouse LEK1 are members of an emerging family of genes that have important and functionally distinct roles in development and cell division.
Footnotes
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↵* This work was supported by National Institutes of Health (NIH) Grants HL37675 (to D. B.) and HL09916 (to R. L. G). Experiments/analysis were performed in part through use of the VUMC Cell Imaging Resource supported by NIH Grants CA68485 and DK20593.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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↵‡ Supported by National Institutes of Health Training Grant HL07723.
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↵§ To whom correspondence should be addressed. Tel.: 615-936-1976; Fax: 615-936-3527; E-mail: david.bader{at}MCMAIL.vanderbilt.edu.
- CENP
- centromere protein
- Rb
- retinoblastoma
- DAPI
- 4,6-diamidino-2-phenylindold
- NLS
- nuclear localization signal
- DMEM
- Dulbecco’s modified eagle medium
- dpc
- days post-coitum
- RT-PCR
- reverse transcription-polymerase chain reaction
- dn-
- dominant-negative
- β-Gal
- β-galactosidase
- Received December 3, 1998.
- Revision received March 8, 1999.
- The American Society for Biochemistry and Molecular Biology, Inc.
