Fission yeast Dis1 is an unconventional TOG/XMAP215 that induces microtubule catastrophe to drive chromosome pulling.

The shortening of microtubules attached to kinetochores is the driving force of chromosome movement during cell division. Specific kinesins are believed to shorten microtubules but are dispensable for viability in yeast, implying the existence of additional factors responsible for microtubule shortening. Here, we demonstrate that Dis1, a TOG/XMAP215 ortholog in fission yeast, promotes microtubule shortening to carry chromosomes.

Ensemble and single-molecule spectroscopic study on excitation energy transfer processes in 1,3-phenylene-linked perylenebisimide oligomers.

1,3-Phenylene-bridged perylenebisimide dimer (PBI2) and trimer (PBI3) were prepared along with monomer reference (PBI1) using perylene imide-anhydride 5 as a key precursor. 3,3-Dimethylbut-1-yl substituents were introduced at the 2,5-positions of perylenebisimide (PBI) to improve the solubilities of PBI oligomers. Actually, no serious aggregation of PBI2 and PBI3 was detected in their dilute CH(2)Cl(2) solutions.

Phase-transfer-catalyzed asymmetric alkylation of alpha-benzoyloxy-beta-keto esters: stereoselective construction of congested 2,3-dihydroxycarboxylic acid esters.

Highly enantioselective phase-transfer-catalyzed alkylation of tert-butyl 2-benzoyloxy-3-oxobutanoate was realized by the use of an N-spiro chiral quaternary ammonium salt, as a complementary approach to the asymmetric hydroxylation of alpha-alkyl-beta-keto esters. The synthetic utility of the alkylated compounds is highlighted by the diastereoselective reduction and alkylation of the remaining ketone moiety to give various enantiomerically enriched congested 2,3-dihydroxycarboxylic acid esters.