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与染色质相关的蛋白质在胞质分裂过程中的分子变化。从海星(Asterina Putinifera)卵母细胞中纯化了NAAP沉淀的核酸相关蛋白，并制备了与NAAP反应的抗体。海星卵母细胞的免疫荧光图像显示，NAAP主要位于卵母细胞的生发泡(核)的核仁中。NAAP的C末端区域已被证明与染色质相关。当海星卵母细胞减数分裂成熟时，NAAP在特定的位置被cdc2激酶磷酸化，并在第一次减数分裂的前后期均匀分布在细胞质中。因此，结论是特定的丝氨酸或苏氨酸残基上的磷酸化使NAAP从染色质中解离出来。

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.