Centromere assembly requires the direct recognition of CENP-A nucleosomes by CENP-N.
Centromeres are specialized chromosomal domains that direct kinetochore assembly during mitosis. CENP-A (centromere protein A), a histone H3-variant present exclusively in centromeric nucleosomes, is thought to function as an epigenetic mark that specifies centromere identity. Here we identify the essential centromere protein CENP-N as the first protein to selectively bind CENP-A nucleosomes but not H3 nucleosomes. CENP-N bound CENP-A nucleosomes in a DNA sequence-independent manner, but did not bind soluble CENP-A-H4 tetramers. Mutations in CENP-N that reduced its affinity for CENP-A nucleosomes caused defects in CENP-N localization and had dominant effects on the recruitment of CENP-H, CENP-I and CENP-K to centromeres. Depletion of CENP-N using siRNA (short interfering RNA) led to similar centromere assembly defects and resulted in reduced assembly of nascent CENP-A into centromeric chromatin. These data suggest that CENP-N interprets the information encoded within CENP-A nucleosomes and recruits other proteins to centromeric chromatin that are required for centromere function and propagation.
Carroll
Christopher W
CW
Department of Biochemistry, Stanford University School of Medicine, Beckman Center, Palo Alto, CA 94503-5307, USA.
Silva
Mariana C C
MC
Godek
Kristina M
KM
Jansen
Lars E T
LE
Straight
Aaron F
AF
D001324:Autoantigens / Q000378:metabolism*; D002460:Cell Line; D002503:Centromere / Q000235:genetics / Q000378:metabolism; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D009707:Nucleosomes / Q000378:metabolism*; D011485:Protein Binding; D034741:RNA, Small Interfering
D001324:Autoantigens; C000619700:CENPA protein, human; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone; D009707:Nucleosomes; D034741:RNA, Small Interfering