CENP-G in neocentromeres and inactive centromeres

GIMELLI G;ZUFFARDI O;GIGLIO, SABRINA RITA;ZENG C. AND HE D.

2000-01-01

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Abstract

CENP-G is a novel constitutive centromere-specific protein localized to the kinetochore inner plate and subjacent region. It has been identified as associating specifically with the α-1 subfamily of α-satellite DNA. In the present work, the localization of CENP-G was compared with that of other CENPs by immunofluorescence and fluorescence in situ hybridization. Studies were carried out on four abnormal human centromeres: two neocentromeres and two inactive centromeres. CENP-G was detected in one of the two inactive centromeres but not in the other that shows a partial deletion of the alphoid DNA. Interestingly, CENP-G is also present in neocentromeres, which lack alphoid DNA sequences, and in the human Y chromosome, which lacks the α-1 type of satellite DNA. These data provide further evidence that CENP-G may be an essential factor in cen- tromeric function and that in centromeres lacking the α-1 subfamily of alphoid DNA, other DNA sequences are able to bind CENP-G.