![]() The budding yeast kinetochore is composed of about 45 core subunits which are organized in different stable complexes ( De Wulf et al., 2003 Westermann et al., 2003) of which several are present in multiple copies ( Joglekar et al., 2006). In contrast, Saccharomyces cerevisiae has point centromeres, which are characterized by a specific ~125 bp DNA sequence wrapped around a single Cse4-containing histone octamer ( Fitzgerald-Hayes et al., 1982 Camahort et al., 2009 Hasson et al., 2013). In humans, regional centromeres span megabases of DNA embedding up to 200 CENP-A containing nucleosomal core particles (NCPs) ( Bodor et al., 2014 Musacchio and Desai, 2017). Kinetochore assembly is restricted to centromeres, chromosomal domains that are marked by the presence of the histone H3 variant Cse4 CENP-A (human ortholog names are superscripted if appropriate) ( Earnshaw and Rothfield, 1985 Fukagawa and Earnshaw, 2014). The physical link between chromosomal DNA and microtubules is the kinetochore, a macromolecular protein complex that mediates the processive binding to depolymerizing microtubules driving the sister chromatids apart into the two emerging cells ( Biggins, 2013 Musacchio and Desai, 2017). Faithful segregation of the duplicated sister chromatids relies on their exclusive attachment to spindle microtubules emerging from opposite spindle poles ( Foley and Kapoor, 2013). Kinetochores enable the precise distribution of chromosomes during the eukaryotic cell division to avoid aneuploidy ( Santaguida and Musacchio, 2009) which is associated with tumorigenesis, congenital trisomies and aging ( Baker et al., 2005 Pfau and Amon, 2012). This study shows molecular characteristics of the point-centromere kinetochore architecture and suggests a role for the Ctf19 C-terminus in mediating CPC-binding and accurate chromosome segregation. ![]() Tethering Sli15 to Ame1/Okp1 rescued synthetic lethality upon Ctf19 depletion in a Sli15 centromere-targeting deficient mutant. The Sli15/Ipl1 INCENP/Aurora-B core-CPC interacted with COMA in vitro through the Ctf19 C-terminus whose deletion affected chromosome segregation fidelity in Sli15 wild-type cells. By performing crosslink-guided in vitro reconstitution of budding yeast kinetochore complexes we showed that the Ame1/Okp1 CENP-U/Q heterodimer, which forms the COMA complex with Ctf19/Mcm21 CENP-P/O, selectively bound Cse4 CENP-A nucleosomes through the Cse4 N-terminus. The inner kinetochore is assembled on CENP-A nucleosomes and has been implicated in establishing a kinetochore-associated pool of Aurora B kinase, a chromosomal passenger complex (CPC) subunit, which is essential for chromosome biorientation. This has lead John Morgan of to conclude that “the main-event-only approach of boxing seems to be a risky approach”.Kinetochores are macromolecular protein complexes at centromeres that ensure accurate chromosome segregation by attaching chromosomes to spindle microtubules and integrating safeguard mechanisms. Juxtapose this with the Pacquiao vs Mosley co-feature, Jorge Arce vs Wilfredo Vazquez, which also proved to be a scintillating affair yet received a miniscule level of publicity, signifying that it did not serve to temper criticism of the main event. This was neatly exemplified by UFC 129, which culminated in a drab main event encounter between Canadian favourite GSP and Jake Shields, though this didn't serve to tarnish the resounding success of the overall occasion given the calibre of the preceding fights (in particular the co-main featuring another title bout in Aldo vs Hominick, and Couture vs Machida). As a result, fans are not generally left with that frustrating feeling of being short-changed. The card is sufficiently deep to ensure that even if the main event and co-main events do not live up to their billing, fans will be compensated lower down the proceedings. ![]() The UFC take things to the proverbial next level. The UFCs presence is palpably felt, and no more so than in Toronto for UFC 129 when Tom Wright oversaw the enactment of operation “Takeover Toronto”, with the pre-event shenanigans commencing an unprecedented 8 days prior to the fights. All of the above serves to beget a buzz that is sadly lacking in boxing. Online we can see Dana Vlogs, fighter Vlogs, Ariel interviews. Apart from the substantive fights, fans are treated to Fan Expos, seminars, Q&As, pre-fight press conferences, weigh-ins (the UFC even seems to maintain the energy and buzz throughout the entire weigh-ins spectacle, whereas in boxing the music ceases when the fighters hit the scales and the fans begin to leave immediately if the main event fighters hit the scales first), pre-fight parties hosted by fighters, Joe Rogan stand-up sets, post-fight pressers and fighter after parties. When the UFC is in town, it becomes more of an extended fan-driven festival than an isolated night of fights.
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