| Summary: | 碩士 === 國立臺灣大學 === 生化科學研究所 === 94 === Synaptonemal complex （SC） is a proteinaceous complex that apparently mediates synapsis between homologous chromosomes during meiotic prophase. In S. cerevisiae, the Zip1 protein is the integral component of SC. In the absence of a DNA double-strand break or the SC initiation protein Zip3, Zip1 proteins aggregate to form a polycomplex （PC）. In addition, Zip1 is also responsible for DSB-independent non-homologous centromere coupling at early meiotic prophase. We report here that Zip3 is a SUMO E3 ligase and that Zip1 is a binding protein for SUMO-conjugated products. Our results also suggest that at early meiotic prophase, Zip1 interacts with Zip3-independent Smt3 conjugates （e.g., Top2） to promote non-homologous centromere coupling. At and after mid-prophase, the Zip1 protein begins to associate with Zip3-dependent Smt3 conjugates （e.g., Red1） along meiotic chromosomes in the wild-type cell to form SCs and with Smt3 polymeric chains in the zip3 mutant to form PCs.
|
|---|
