The Drosophila RAD21 cohesin persists at the centromere region in mitosis.
'Cohesin' is a highly conserved multiprotein complex thought to be the primary effector of sister-chromatid cohesion in all eukaryotes. Cohesin complexes in budding yeast hold sister chromatids together from S phase until anaphase, but in metazoans, cohesin proteins dissociate from chromosomes and redistribute into the whole cell volume during prophase, well before sister chromatids separate (reviewed in [1,2]). Here we address this apparent anomaly by investigating the cell-cycle dynamics of DRAD21, the Drosophila orthologue of the Xenopus XRAD21 and Saccharomyces cerevisiae Scc1p/Mcd1p cohesins [3]. Analysis of DRAD21 in S2 Drosophila tissue culture cells and live embryos expressing a DRAD21-green fluorescent protein (GFP) fusion revealed the presence of four distinct subcellular pools of DRAD21: a cytoplasmic pool; a chromosome-associated pool which dissociates from chromatin as chromosomes condense in prophase; a short-lived centrosome-associated pool present during metaphase-anaphase; and a centromere-proximal pool which remains bound to condensed chromosomes, is found along the junction of sister chromatids between kinetochores, and persists until the metaphase-anaphase transition. We conclude that in Drosophila, and possibly all metazoans, a minor pool of cohesin remains bound to centromere-proximal chromatin after prophase and maintains sister-chromatid cohesion until the metaphase-anaphase transition.
Warren
W D
WD
Peter MacCallum Cancer Institute, St Andrews Place, East, Victoria 3002, Melbourne, Australia. w.warren@pmci.unimelb.edu.au
Steffensen
S
S
Lin
E
E
Coelho
P
P
Loupart
M
M
Cobbe
N
N
Lee
J Y
JY
McKay
M J
MJ
Orr-Weaver
T
T
Heck
M M
MM
Sunkel
C E
CE
D000818:Animals; D051017:Apoptosis Regulatory Proteins; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002460:Cell Line; D002503:Centromere / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone; D004330:Drosophila; D029721:Drosophila Proteins; D005656:Fungal Proteins; D008938:Mitosis / Q000502:physiology; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D029867:Xenopus Proteins; D000097722:Cohesins
D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D029867:Xenopus Proteins; D000097722:Cohesins; C490529:MCD1 protein, S cerevisiae; C490528:Rad21 protein, Xenopus; C410884:vtd protein, Drosophila