The acetyltransferase activity of San stabilizes the mitotic cohesin at the centromeres in a shugoshin-independent manner.
Proper sister chromatid cohesion is critical for maintaining genetic stability. San is a putative acetyltransferase that is important for sister chromatid cohesion in Drosophila melanogaster, but not in budding yeast. We showed that San is critical for sister chromatid cohesion in HeLa cells, suggesting that this mechanism may be conserved in metazoans. Furthermore, although a small fraction of San interacts with the NatA complex, San appears to mediate cohesion independently. San exhibits acetyltransferase activity in vitro, and its activity is required for sister chromatid cohesion in vivo. In the absence of San, Sgo1 localizes correctly throughout the cell cycle. However, cohesin is no longer detected at the mitotic centromeres. Furthermore, San localizes to the cytoplasm in interphase cells; thus, it may not gain access to chromosomes until mitosis. Moreover, in San-depleted cells, further depletion of Plk1 rescues the cohesion along the chromosome arms, but not at the centromeres. Collectively, San may be specifically required for the maintenance of the centromeric cohesion in mitosis.
Hou
Fajian
F
Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Chu
Chih-Wen
CW
Kong
Xiangduo
X
Yokomori
Kyoko
K
Zou
Hui
H
D000123:Acetyltransferases / Q000378:metabolism* / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism* / Q000502:physiology*; D002503:Centromere / Q000201:enzymology*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D063213:N-Terminal Acetyltransferase E; D009687:Nuclear Proteins / Q000378:metabolism*; D000097722:Cohesins
D000123:Acetyltransferases; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D063213:N-Terminal Acetyltransferase E; D009687:Nuclear Proteins; D000097722:Cohesins; C496644:SGO1 protein, human; C520714:NAA50 protein, human