Novel components of human mitotic chromosomes identified by proteomic analysis of the chromosome scaffold fraction.
Chromosomal nonhistone proteins have important roles in mitotic chromosome formation and dynamics. In order to identify novel abundant proteins with a potential involvement in these processes, we initiated a proteomic screen of the chromosome scaffold fraction. This screen identified 79 proteins, 30 of which had not previously been described as components of mitotic chromosomes. Furthermore, half of these proteins had no documented function. We analyzed the cell-cycle dependent distribution of three uncharacterized proteins by expressing them as green fluorescent protein (GFP) fusions and showed that they associate with mitotic chromosomes in vivo. One of the proteins, nuclear protein p30, is a novel component of the inner centromere. Over-expression experiments indicated that p30 may have an active role in the formation of centromeric heterochromatin.
Gassmann
Reto
R
Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Kings Buildings, Mayfield Road, Edinburgh, EH9 3JR, UK.
Henzing
Alexander J
AJ
Earnshaw
William C
WC
D002453:Cell Cycle; D002503:Centromere / Q000378:metabolism*; D002877:Chromosomes, Human / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006570:Heterochromatin / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D008938:Mitosis / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D006570:Heterochromatin; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins