title: CENP-B binds a novel centromeric sequence in the Asian mouse Mus caroli.
abstract: Minor satellite DNA, found at Mus musculus centromeres, is not present in the genome of the Asian mouse Mus caroli. This repetitive sequence family is speculated to have a role in centromere function by providing an array of binding sites for the centromere-associated protein CENP-B. The apparent absence of CENP-B binding sites in the M. caroli genome poses a major challenge to this hypothesis. Here we describe two abundant satellite DNA sequences present at M. caroli centromeres. These satellites are organized as tandem repeat arrays, over 1 Mb in size, of either 60- or 79-bp monomers. All autosomes carry both satellites and small amounts of a sequence related to the M. musculus major satellite. The Y chromosome contains small amounts of both major satellite and the 60-bp satellite, whereas the X chromosome carries only major satellite sequences. M. caroli chromosomes segregate in M. caroli x M. musculus interspecific hybrid cell lines, indicating that the two sets of chromosomes can interact with the same mitotic spindle. Using a polyclonal CENP-B antiserum, we demonstrate that M. caroli centromeres can bind murine CENP-B in such an interspecific cell line, despite the absence of canonical 17-bp CENP-B binding sites in the M. caroli genome. Sequence analysis of the 79-bp M. caroli satellite reveals a 17-bp motif that contains all nine bases previously shown to be necessary for in vitro binding of CENP-B. This M. caroli motif binds CENP-B from HeLa cell nuclear extract in vitro, as indicated by gel mobility shift analysis. We therefore suggest that this motif also causes CENP-B to associate with M. caroli centromeres in vivo. Despite the sequence differences, M. caroli presents a third, novel mammalian centromeric sequence producing an array of binding sites for CENP-B.
authors.affiliation: MRC Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Kipling
authors.forename: A R
authors.initials: AR
authors.lastname: Mitchell
authors.forename: H
authors.initials: H
authors.lastname: Masumoto
authors.forename: H E
authors.initials: HE
authors.lastname: Wilson
authors.forename: L
authors.initials: L
authors.lastname: Nicol
authors.forename: H J
authors.initials: HJ
authors.lastname: Cooke
mesh_terms: D000818:Animals; D001324:Autoantigens; D001483:Base Sequence; D015139:Blotting, Southern; D002503:Centromere / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D002875:Chromosomes / Q000648:ultrastructure; D003001:Cloning, Molecular; D004276:DNA, Satellite / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D014644:Genetic Variation; D006801:Humans; D006822:Hybrid Cells; D017404:In Situ Hybridization, Fluorescence; D051379:Mice / Q000235:genetics; D008969:Molecular Sequence Data; D009115:Muridae / Q000235:genetics*; D015345:Oligonucleotide Probes; D011485:Protein Binding; D013045:Species Specificity
chemical_list: D001324:Autoantigens; C497926:CENPB protein, human; C497927:Cenpb protein, mouse; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D004276:DNA, Satellite; D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes