Meiotic proteins bqt1 and bqt2 tether telomeres to form the bouquet arrangement of chromosomes.
In many organisms, meiotic chromosomes are bundled at their telomeres to form a "bouquet" arrangement. The bouquet formation plays an important role in homologous chromosome pairing and therefore progression of meiosis. As meiotic telomere clustering occurs in response to mating pheromone signaling in fission yeast, we looked for factors essential for bouquet formation among genes induced under mating pheromone signaling. This genome-wide search identified two proteins, Bqt1 and Bqt2, that connect telomeres to the spindle-pole body (SPB; the centrosome equivalent in fungi). Neither Bqt1 nor Bqt2 alone functions as a connector, but together the two proteins form a bridge between Rap1 (a telomere protein) and Sad1 (an SPB protein). Significantly, when both Bqt1 and Bqt2 are ectopically expressed in mitotic cells, they also form a bridge between Rap1 and Sad1. Thus, a complex including Bqt1 and Bqt2 is essential for connecting telomeres to the SPB.
Chikashige
Yuji
Y
Cell Biology Group and CREST Research Project, Kansai Advanced Research Center, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe 651-2492, Japan.
Tsutsumi
Chihiro
C
Yamane
Miho
M
Okamasa
Kasumi
K
Haraguchi
Tokuko
T
Hiraoka
Yasushi
Y
D002467:Cell Nucleus / Q000378:metabolism; D023902:Chromosome Pairing; D015825:Chromosomes, Fungal / Q000378:metabolism*; D020829:Equisetum / Q000378:metabolism; D016681:Genome, Fungal / Q000235:genetics; D008540:Meiosis; D008957:Models, Genetic; D010641:Phenotype; D011418:Prophase; D012568:Schizosaccharomyces / Q000166:cytology; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*; D000089804:Shelterin Complex; D016615:Telomere / Q000378:metabolism*; D034501:Telomere-Binding Proteins / Q000378:metabolism*
C510171:Bqt1 protein, S pombe; C510172:Bqt2 protein, S pombe; C509571:Rap1 protein, S pombe; C093512:SAD1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins