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Bir1/Cut17 moving from chromosome to spindle upon the loss of cohesion is required for condensation, spindle elongation and repair
Author(s) -
Morishita Jun,
Matsusaka Takahiro,
Goshima Gohta,
Nakamura Takahiro,
Tatebe Hisashi,
Yanagida Mitsuhiro
Publication year - 2001
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1046/j.1365-2443.2001.00459.x
Subject(s) - establishment of sister chromatid cohesion , microbiology and biotechnology , biology , spindle pole body , prometaphase , kinetochore , cohesin , anaphase , spindle apparatus , metaphase , premature chromosome condensation , mitosis , aurora b kinase , genetics , chromatin , cell cycle , chromosome , cell division , dna , cell , gene
Background In mammals, proteins containing BIR domains (IAPs and survivin) are implicated in inhibiting apoptosis and sister chromatid separation. In the nematode, Bir1 is required for a proper localization of aurora kinase, which moves from the mitotic chromosome in metaphase to the spindle midzone in anaphase as a passenger. Fission yeast Bir1/Pbh1 is essential for normal mitosis. Results A temperature sensitive mutant cut17‐275 exhibits the defect in condensation and spindle elongation at 36 °C, while securin is degraded. Gene cloning shows that the cut17 + gene is identical to bir1 + / pbh1 + . At 26 °C, cut17‐275 is UV sensitive as the repair of DNA damage is severely compromised. Bir1/Cut17 is a nuclear protein in interphase, which is then required for recruiting condensin to the mitotic nucleus, and concentrates to form a discrete number of dots from prometaphase to metaphase. Once the chromatids are separated, Bir1/Cut17 no longer binds to kinetochores and instead moves to the middle of spindle. Chromatin immunoprecipitation suggested that Bir1/Cut17 associates with the outer repetitious centromere region in metaphase. Following the initiation of anaphase the protein switches from being a chromosomal protein to a spindle protein. This transit is stringently regulated by the state of sister chromatid cohesion proteins Mis4 and Rad21. Ark1, is an aurora kinase homologue whose mitotic distribution is identical to, and under the control of Bir1/Cut17. Conclusions Bir1/Cut17 and Ark1 act as ‘passengers’ but they may play a main role as a recruitment factor, essential for condensation, spindle elongation and DNA repair. Bir1/Cut17 should have roles both in mitotic and in interphase chromosome. The proper location of Ark1 requires Bir1/Cut17, and the mitotic localization of Bir1/Cut17 requires sister cohesion.