Nakamura Y, Takeda M, Nishimura T
Department of Neuropsychiatry, Osaka University Medical School, Japan.
Neurosci Lett. 1996 Feb 23;205(2):91-4. doi: 10.1016/0304-3940(96)12382-x.
Recently, the dynamic features of the intermediate filaments (IF) have been revealed. The effect of phosphorylation on the dynamics of bovine glial fibrillary acidic protein (GFAP), the astroglial IF, was studied in vitro with fluorescently labeled GFAP. Soluble GFAP in low ionic strength buffer was rapidly and fully phosphorylated to be used as phosphorylated GFAP. Assembly of GFAP was observed to be inhibited in proportion to the extent of phosphorylation by mixing phosphorylated and non-phosphorylated GFAP at various ratios, and phosphorylated GFAP could not be assembled with non-phosphorylated GFAP into filaments at all. Furthermore, the subunit exchange was suppressed in proportion to the extent of phosphorylation. Phosphorylation affects the dynamic equilibrium of GFAP, and contributes to breaking down GFAP frameworks in mitotic glial cells.
最近，中间丝（IF）的动态特性已被揭示。利用荧光标记的胶质纤维酸性蛋白（GFAP，星形胶质细胞中间丝），在体外研究了磷酸化对其动力学的影响。低离子强度缓冲液中的可溶性GFAP被快速完全磷酸化，用作磷酸化的GFAP。通过以不同比例混合磷酸化和未磷酸化的GFAP，观察到GFAP的组装受到抑制，且抑制程度与磷酸化程度成正比，磷酸化的GFAP根本无法与未磷酸化的GFAP组装成丝。此外，亚基交换也与磷酸化程度成比例地受到抑制。磷酸化影响GFAP的动态平衡，并有助于破坏有丝分裂胶质细胞中的GFAP框架。
