Expression profiles of histone point mutants
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ABSTRACT: Accurate chromosome segregation requires that sister kinetochores biorient and attach to microtubules from opposite poles. Kinetochore biorientation relies on the underlying centromeric chromatin, which provides a platform to assemble the kinetochore and to recruit the regulatory factors that ensure the high fidelity of this process. To identify the centromeric chromatin determinants that contribute to chromosome segregation, we performed two complementary unbiased genetic screens using a library of mutants in every residue of histone H3 and H4. In one screen, we identified mutants that lead to increased loss of a non-essential chromosome. In the second screen, we isolated mutants whose viability depends on a key regulator of biorientation, the Aurora B protein kinase. Nine mutations, H3 Q5A, H3 R40A, H3 G44A, H3 R53A, H3 N108A, H3 L109A, H4 K44A, H4 V81A, and H4 Y98A, were common to both screens and exhibited kinetochore biorientation defects. Five of the mutants map near the unstructured nucleosome entry site and their genetic interaction with decreased Ipl1 function can be suppressed by increasing the dosage of the Sgo1 protein. In addition, the composition of purified kinetochores was altered in five of the mutants. Together, this work identifies previously unknown histone residues involved in chromosome segregation and lays the foundation for future studies of the role of the underlying chromatin structure in segregation.
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE39903 | GEO | 2013/12/04
SECONDARY ACCESSION(S): PRJNA172006
REPOSITORIES: GEO
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