Garbuglia M, Verzini M, Dimlich R V, Jamieson G A, Donato R
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy.
Biochim Biophys Acta. 1996 Oct 11;1313(3):268-76. doi: 10.1016/0167-4889(96)00099-7.
We have investigated the interaction of S-100 proteins (beta and/or alpha) and annexin II2-p11(2) with glial fibrillary acidic protein (GFAP) and desmin to have further information on the mechanisms whereby S-100 proteins and annexin II2-p11(2) affect assembly/disassembly of GFAP and desmin intermediate filaments (IFs). Analyses were conducted on either native IF subunits, GFAP or desmin rod domain, or headless GFAP or desmin. Our data indicate that: (i) S-100 proteins bind to GFAP and desmin N-terminal head domain; (ii) annexin II2-p11(2) binds to GFAP rod domain; (iii) annexin II2-p11(2) does not interact with desmin nor affects desmin assembly. The present data suggest that the ability of S-100 proteins to inhibit GFAP and desmin assemblies and to promote the disassembly of preformed GFAP and desmin IFs depends on occupation of a site on the N-terminal head domain of these IF subunit. It is known that the N-terminal head domain is critical for the progression from the stage of GFAP and desmin dimers/tetramers to that of large oligomers. On the other hand, the ability of annexin II2-p11(2) to stimulate GFAP assembly under conditions where this latter is normally hampered (e.g., at alkaline pH values) might depend on annexin II2-p11(2)-induced changes in the structure of GFAP rod domain, possibly as a consequence of charge modifications. By contrast, the inability of annexin II2-p11(2) to bind to desmin would depend on desmin resistance to charge modifications.
我们研究了S-100蛋白（β和/或α）以及膜联蛋白II2-p11(2)与胶质纤维酸性蛋白（GFAP）和结蛋白的相互作用，以进一步了解S-100蛋白和膜联蛋白II2-p11(2)影响GFAP和结蛋白中间丝（IFs）组装/解聚的机制。对天然IF亚基、GFAP或结蛋白杆状结构域，或无头GFAP或结蛋白进行了分析。我们的数据表明：（i）S-100蛋白与GFAP和结蛋白的N端头部结构域结合；（ii）膜联蛋白II2-p11(2)与GFAP杆状结构域结合；（iii）膜联蛋白II2-p11(2)不与结蛋白相互作用，也不影响结蛋白的组装。目前的数据表明，S-100蛋白抑制GFAP和结蛋白组装以及促进预先形成的GFAP和结蛋白IFs解聚的能力取决于占据这些IF亚基N端头部结构域上的一个位点。已知N端头部结构域对于从GFAP和结蛋白二聚体/四聚体阶段发展到大型寡聚体阶段至关重要。另一方面，膜联蛋白II2-p11(2)在通常受到阻碍的条件下（例如在碱性pH值下）刺激GFAP组装的能力可能取决于膜联蛋白II2-p11(2)诱导的GFAP杆状结构域结构变化，这可能是电荷修饰的结果。相比之下，膜联蛋白II2-p11(2)不能与结蛋白结合将取决于结蛋白对电荷修饰的抗性。
