This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A critical aspect of mitosis is the capture and correct attachment of the kinetochores by the dynamic microtubules (MTs) of the spindle. Attachment is established between the plus-ends of MTs and the kinetochore, a proteinaceous structure assembled on the centromeric DNA. We identified the essential fission yeast kinetochore protein Spc7p as a suppressor of the MT-plus-end localised protein Mal3p, which belongs to the highly conserved EB1 family. Spc7 and Mal3 interact genetically as well as physically, and the expression of mutant versions of Spc7 results in severe defects in the association of kinetochores with MTs. Genetic analysis indicates that Spc7 might regulate microtubule dynamics. Furthermore Spc7 is required for the correct formation and function of the mitotic spindle, and mutants in spc7 give rise to severe spindle abnormalities at all stages of mitosis. Nearly 50% of mutant spc7 mitotic cells had abnormal spindles. These range from monopolar spindles to cells showing an inability to elongate the spindle at the meta/anaphase transition, as well as breakage and reassembly of elongating anaphase spindles. Preliminary tomographic data of anaphase spindles show spindles that are too long, causing panhandle-like protrusions from the nucleus. At the end of these panhandles are the spindle pole bodies (SPBs), which look normal. In upcoming work we will use tomography to analyse the number and lengths of spindle and kinetochore MTs at various stages of mitosis, as well as to characterize the abnormalities that are not evident at the resolution of the light microscope.
| Giddings Jr, Thomas H; Morphew, Mary K; McIntosh, J Richard (2017) Preparing Fission Yeast for Electron Microscopy. Cold Spring Harb Protoc 2017: |
| Zhao, Xiaowei; Schwartz, Cindi L; Pierson, Jason et al. (2017) Three-Dimensional Structure of the Ultraoligotrophic Marine Bacterium ""Candidatus Pelagibacter ubique"". Appl Environ Microbiol 83: |
| Brown, Joanna R; Schwartz, Cindi L; Heumann, John M et al. (2016) A detailed look at the cytoskeletal architecture of the Giardia lamblia ventral disc. J Struct Biol 194:38-48 |
| Saheki, Yasunori; Bian, Xin; Schauder, Curtis M et al. (2016) Control of plasma membrane lipid homeostasis by the extended synaptotagmins. Nat Cell Biol 18:504-15 |
| Höög, Johanna L; Lacomble, Sylvain; Bouchet-Marquis, Cedric et al. (2016) 3D Architecture of the Trypanosoma brucei Flagella Connector, a Mobile Transmembrane Junction. PLoS Negl Trop Dis 10:e0004312 |
| Park, J Genevieve; Palmer, Amy E (2015) Properties and use of genetically encoded FRET sensors for cytosolic and organellar Ca2+ measurements. Cold Spring Harb Protoc 2015:pdb.top066043 |
| McCoy, Kelsey M; Tubman, Emily S; Claas, Allison et al. (2015) Physical limits on kinesin-5-mediated chromosome congression in the smallest mitotic spindles. Mol Biol Cell 26:3999-4014 |
| Höög, Johanna L; Lötvall, Jan (2015) Diversity of extracellular vesicles in human ejaculates revealed by cryo-electron microscopy. J Extracell Vesicles 4:28680 |
| Marc, Robert E; Anderson, James R; Jones, Bryan W et al. (2014) The AII amacrine cell connectome: a dense network hub. Front Neural Circuits 8:104 |
| Weber, Britta; Tranfield, Erin M; Höög, Johanna L et al. (2014) Automated stitching of microtubule centerlines across serial electron tomograms. PLoS One 9:e113222 |
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