Comprehensive analysis of the ICEN (Interphase Centromere Complex) components enriched in the CENP-A chromatin of human cells.
The centromere is a chromatin structure essential for correct segregation of sister chromatids, and defects in this region often lead to aneuploidy and cancer. We have previously reported purification of the interphase centromere complex (ICEN) from HeLa cells, and have demonstrated the presence of 40 proteins (ICEN1-40), along with CENP-A, -B, -C, -H and hMis6, by proteomic analysis. Here we report analysis of seven ICEN components with unknown function. Centromere localization of EGFP-tagged ICEN22, 24, 32, 33, 36, 37 and 39 was observed in transformant cells. Depletion of each of these proteins by short RNA interference produced abnormal metaphase cells carrying misaligned chromosomes and also produced cells containing aneuploid chromosomes, implying that these ICEN proteins take part in kinetochore functions. Interestingly, in the ICEN22, 32, 33, 37 or 39 siRNA-transfected cells, CENP-H and hMis6 signals disappeared from all the centromeres in abnormal mitotic cells containing misaligned chromosomes. These results suggest that the seven components of the ICEN complex are predominantly localized at the centromeres and are required for kinetochore function perhaps through or not through loading of CENP-H and hMis6 onto the centromere.
Izuta
Hiroshi
H
Bioscience and Biotechnology Center, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan.
Ikeno
Masashi
M
Suzuki
Nobutaka
N
Tomonaga
Takeshi
T
Nozaki
Naohito
N
Obuse
Chikashi
C
Kisu
Yasutomo
Y
Goshima
Naoki
N
Nomura
Fumio
F
Nomura
Nobuo
N
Yoda
Kinya
K
D000782:Aneuploidy; D001324:Autoantigens / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002503:Centromere / Q000235:genetics / Q000378:metabolism*; D000076247:Centromere Protein A; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007399:Interphase; D018386:Kinetochores / Q000378:metabolism; D008677:Metaphase / Q000235:genetics; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D034622:RNA Interference; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D001324:Autoantigens; C000619700:CENPA protein, human; C121933:CENPH protein, human; C484297:CENPI protein, human; C495719:CENPM protein, human; D018797:Cell Cycle Proteins; D000076247:Centromere Protein A; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins