【摘要】 在真核细胞中普遍存在中间纤维(IF),不同类细胞的中间纤维都有相似的“头部+1A+L1+1B+L1-2+2A+L2+2B+尾部”结构,其中:头部有一个β-折叠区,1A上有七个残基的亚结构,1B和2A+L2+2B上有规则的轴向排列的氨基酸残基;2B的α-螺旋C末端有一个高度保守的氨基酸残基框,这些结构都有其独特的功能。各种IF组装方式不同,但至少都经历了非纤维性颗粒、波形短纤维和长纤维的形态变化过程。研究发现,IF具有阻止细胞凋亡的功能;在细胞凋亡过程中IF发生磷酸化和降解;细胞质中间纤维(CIF)在染色质-核纤层/CIF结合中发挥DNA选择功能。更多还原

【Abstract】 Intermediate filament (IF), which has similar second-degree structure: head domain+1A+L1+1B+L1-2+2A+L2+2B+tail domain, exists widely in eukaryotic cells. Several substructures of the second-degree structure, the β-strand region of the head domain , the heptad substructure of segment 1A, regular axial disposition of amino acid residues in segment 1B and 2A+L2+2B, a highly conserved amino acid motif of the C-terminal tail domain of the segment 2B, have their special functions. The assembly styles of various kinds of IFs are different, but the transition of assembly stages, from non-filamentous particles and short fibrous squiggles to long fibrils, is similar. IF can resist to cell apoptosis. The structure of IF undergoes phosphorylation and degradation during the cell apoptosis. The cytoplasmic intermediate filament (GIF) might generally exert a DNA-selecting function in such chromatin-lamina/CIF association.更多还原