MOLECULAR AND CELLULAR STUDIES OF MOLECULAR CHANGES OF PROTEINS ASSOCIATED WITH CHROMATIN DURING CYTOKINESIS

利用海星卵和胚胎研究了细胞分裂过程中染色质相关蛋白的分子变化。从海星卵母细胞中纯化了核酸相关蛋白介导的NAAP，制备了与NAAP反应的抗体。海星卵母细胞的免疫荧光图像显示NAAP主要位于卵母细胞生发囊（核）的核仁中。NAAP的c端区域已被证明与染色质有关。当海星卵母细胞经历减数分裂成熟时，NAAP在特定位点被cdc2激酶磷酸化，并在第一次减数分裂的前前期至后期均匀分布于细胞质中。因此，可以得出结论，在特定的丝氨酸或苏氨酸残基上的磷酸化使NAAP与染色质分离。

Molecular changes of proteins associated with chromatin during cytokinesis have been studied using starfish eggs and embryos. Nucleic acid-associated protein sedignated NAAP has been purified from starfish (Asterina pectinifera) oocytes and an antibody reacting with NAAP has been prepared. Immunofluorscence images of starfish oocytes show that NAAP is primarily located in the nucleolus of the germinal vesicle (nucleus) of the oocyte. The C-terminal region of NAAP has been shown to be associated with chromatin. When starfish oocytes undergo meiotic maturation NAAP is phosphorylated by cdc2 kinase at specific sites and distributed evenly in the cytoplasm at the first meiotic prometa- to anaphases during the first meiotic division. Therefore, it is concluded that phospharylation at specific Ser or Thr residues dissociates NAAP fron chromatin.