Open AccessI ml3p, a component of the C tf19 complex of the budding yeast kinetochore is required to maintain kinetochore integrity under conditions of spindle stress
Author(s) -
Lahiri Sudeshna,
Mehta Gunjan D.,
Ghosh Santanu Kumar
Publication year - 2013
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/1567-1364.12041
Subject(s) - kinetochore , biology , microbiology and biotechnology , centromere , mitosis , chromosome segregation , microtubule , minichromosome , mitotic exit , saccharomyces cerevisiae , genetics , spindle apparatus , cell division , chromosome , gene , cell
The C tf19 multi‐protein complex of the central kinetochore in S accharomyces cerevisiae is required for precise chromosome segregation during mitosis. Of 11 proteins of this complex, at least six are required for cell survival when microtubules are defective. To find individual roles of these proteins in kinetochore stability, double deletion mutants of the corresponding genes were constructed in several combinations. The growth phenotype of all the mutants was in accordance with the current model of hierarchical assembly of kinetochore proteins except one that lacked CHL4 and IML3 genes in a tubulin‐defective background ( tub1‐1 chl4 iml3) . tub1‐1 chl4 iml3 showed synergistic growth defect, decrease in minichromosome stability compared with its single mutants, and a greater accumulation of cells at the G 2/ M checkpoint of the cell cycle. Furthermore, in the absence of I ml3p, the two‐hybrid interaction between C tf19p (a member of the C tf19 complex) and D am1p (a member of the outer kinetochore DASH complex) was disrupted and the localization of D am1p at the kinetochore was also compromised. These results indicate a role for I ml3p distinct from C hl4p at the kinetochore. I ml3p may be acting as a link between the central and the outer complexes thus contributing to a functional kinetochore.