Kerry S. Bloom

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Microtubule assembly in Saccharomyces cerevisiae is initiated from sites within spindle pole bodies (SPBs) in the nuclear envelope. Microtubule plus ends are thought to be organized distal to the SPBs, while minus ends are proximal. Several hypotheses for the function of microtubule motor proteins in force generation and regulation of microtubule assembly(More)
Localization of dynein-green fluorescent protein (GFP) to cytoplasmic microtubules allowed us to obtain one of the first views of the dynamic properties of astral microtubules in live budding yeast. Several novel aspects of microtubule function were revealed by time-lapse, three-dimensional fluorescence microscopy. Astral microtubules, about four to six in(More)
Kinetochore attachment to spindle microtubule plus-ends is necessary for accurate chromosome segregation during cell division in all eukaryotes. The centromeric DNA of each chromosome is linked to microtubule plus-ends by eight structural-protein complexes. Knowing the copy number of each of these complexes at one kinetochore–microtubule attachment site is(More)
In the budding yeast Saccharomyces cerevisiae the mitotic spindle must be positioned along the mother-bud axis to activate the mitotic exit network (MEN) in anaphase. To examine MEN proteins during mitotic exit, we imaged the MEN activators Tem1p and Cdc15p and the MEN regulator Bub2p in vivo. Quantitative live cell fluorescence microscopy demonstrated the(More)
Using green fluorescent protein probes and rapid acquisition of high-resolution fluorescence images, sister centromeres in budding yeast are found to be separated and oscillate between spindle poles before anaphase B spindle elongation. The rates of movement during these oscillations are similar to those of microtubule plus end dynamics. The degree of(More)
BACKGROUND Eukaryotic cells localize selected mRNAs to a region of the cell as a means to sequester proteins. Signals within the 3' untranslated region (3' UTR) facilitate mRNA localization by both actin and microtubule cytoskeletal systems. Recently, an mRNA in the yeast Saccharomyces cerevisiae, ASH1, was shown to coalesce into a discrete particle that is(More)
We have examined the chromatin structure of the centromere regions of chromosomes III and XI in yeast by using cloned functional centromere DNAs (CEN3 and CEN11) as labeled probes. When chromatin from isolated nuclei is digested with micrococcal nuclease and the resulting DNA fragments separated electrophoretically and blotted to nitrocellulose filters, the(More)
Cse4 is the budding yeast homologue of CENP-A, a modified histone H3 that specifies the base of kinetochores in all eukaryotes. Budding yeast is unique in having only one kinetochore microtubule attachment site per centromere. The centromere is specified by CEN DNA, a sequence-specific binding complex (CBF3), and a Cse4-containing nucleosome. Here we(More)
Conditional temperature-sensitive (ts) mutations are valuable reagents for studying essential genes in the yeast Saccharomyces cerevisiae. We constructed 787 ts strains, covering 497 (∼45%) of the 1,101 essential yeast genes, with ∼30% of the genes represented by multiple alleles. All of the alleles are integrated into their native genomic locus in the(More)
The budding yeast kinetochore is comprised of >60 proteins and associates with 120 bp of centromeric (CEN) DNA. Kinetochore proteins are highly dynamic and exhibit programmed cell cycle changes in localization. The CEN-specific histone, Cse4p, is one of a few stable kinetochore components and remains associated with CEN DNA throughout mitosis. In contrast,(More)