Identification of a subdomain of CENP-B that is necessary and sufficient for localization to the human centromere.
We have combined in vivo and in vitro approaches to investigate the function of CENP-B, a major protein of human centromeric heterochromatin. Expression of epitope-tagged deletion derivatives of CENP-B in HeLa cells revealed that a single domain less than 158 residues from the amino terminus of the protein is sufficient to localize CENP-B to centromeres. Centromere localization was abolished if as few as 28 amino acids were removed from the amino terminus of CENP-B. The centromere localization signal of CENP-B can function in an autonomous fashion, relocating a fused bacterial enzyme to centromeres. The centromere localization domain of CENP-B specifically binds in vitro to a subset of alpha-satellite DNA monomers. These results suggest that the primary mechanism for localization of CENP-B to centromeres involves the recognition of a DNA sequence found at centromeres. Analysis of the distribution of this sequence in alpha-satellite DNA suggests that CENP-B binding may have profound effects on chromatin structure at centromeres.
Pluta
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AF
Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Saitoh
N
N
Goldberg
I
I
Earnshaw
W C
WC
D001324:Autoantigens; D001483:Base Sequence; D002503:Centromere / Q000737:chemistry*; D051936:Centromere Protein B; D002843:Chromatin / Q000737:chemistry*; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis*; D004268:DNA-Binding Proteins / Q000032:analysis*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation
D001324:Autoantigens; C497926:CENPB protein, human; D051936:Centromere Protein B; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins