S100A4蛋白可干擾S100A1蛋白和the RAGE V domain結合抑制細胞增生

人類S100蛋白質家族具有EF-hand結構(helix-loop-helix)的小分子量酸性蛋白質家族，結構上在C端具有與Ca2+結合的canonical EF-hand，在N端則具有S100特有的pseudo EF結構。該系列至少20種，存在於脊椎動物特定組織與細胞中，平均分子量大約在9-13 kDa間。S100蛋白質通常形成homodimer，也可以形成heterodimer。研究顯示，S100A1及S100A4都可以與RAGE蛋白上的V-domain 結合，而S100蛋白質家族中所有的蛋白質在水溶液都以dimer存在，而每一個S100A1 (或S100A4)的homodimer會與2個RAGE結合，而造成2個RAGE蛋白的cytoplasmid domain 相互靠近，進而產生相互磷酶化(autophosphorylation）現象，終導致訊號傳遞發生，而造成細胞之增生（cell proliferation）。研究也顯示S100A1 與S100A4 是相互拮抗的。本實驗藉由HADDOCK的計算，可得兩蛋白質形成的heterodimer的三維結構圖，以及兩蛋白質反應的作用面，也顯示了S100A1蛋白質與S100A4蛋白質形成heterodimer時，S100A1蛋白質與S100A4蛋白質的相互結合區域正好是S100A1與V-domain 的結合區域。再藉由螢光與等溫滴定微量熱法(ITC)測量兩蛋白質的解離常數(Kd)，最後由WST-1 Assay可得S100A1-S100A4 的heterodimer是不具細胞增生的活性，及形成heterodimer之後他就喪失了細胞增生的生物活性。也證明了S100A4蛋白質確實具有阻斷S100A1與其他蛋白質結合的能力。

關鍵字

S100A4 蛋白質； S100A1 蛋白質； S100A4與S100A1蛋白質

並列摘要

S100A1 is a homodimeric protein that belongs to the S100 subfamily of EF hand of calcium binding protein. Upon Ca2+ binding to S100A1 EF-hand motifs, the conformation of S100A1 change promoting interaction with target proteins. V domain of receptors for the advanced glycation end products(V domain of RAGE) is one of the target proteins for S100A1 binding to its hydrophobic surface and further triggers signaling transduction cascades that induces cell growth, cell proliferation, and tumorigenesis. The present study describes S100A4 and S100A1 can become dimer and can mutual antagonist each other. In this study, we elucidated the structural interactions between S100A4 and S100A1. We employed a variety of biophysical techniques, including fluorescence spectroscopy, multidimensional NMR spectroscopy, HADDOCK, isothermal titration calorimeter(ITC) mutagenesis study and functional assay to characterize the interaction between S100A4 and S100A1. The binding constant was determined from fluorescence spectroscopy and ITC. The binding interfaces upon complex formation of S100A4 and S100A1 mapping from 15N-1H HSQC titration. Further HADDOCK modeling and mutagenesis study study and functional assay indicated the role of important residues of S100A4 protein for S100A1 protein interactions. In this study, we also find the S100A4 become blocker between S100A1 and V-domain that is also supported by WST-1 cell proliferation.

並列關鍵字

S100A4 protein ； S100A1 protein ； S100A1 protein and S100A4 protein

參考文獻

[27] Li G, Barthelemy A, Feng G, Gentil-Perret A, Peoc'h M, Genin C, et al. S100A1: A powerful marker to.differentiate chromophobe renal cell carcinoma from renal oncocytoma. Histopathology. 2007; 50: 642±647. https://doi.org/10.1111/j.1365-2559.2007.02655.x PMID: 17394501

[28]Adhikari BB, Wang K. S100A1 modulates skeletal muscle contraction by desensitizing calcium activation of isometric tension, stiffness and ATPase. FEBS Lett. 2001; 497:95±98.https://doi.org/10.1016/S0014-5793(01)02444-9 PMID: 11377420

S100A1 and S100A6 in postnatally developing salivary glands of rats. Histochem Cell Biol. 1998; 110:579±587. https://doi.org/10.1007/s004180050320 PMID: 9860256

survival. Am J Clin Pathol. 2009; 132: 846±856. https://doi.org/10.1309/AJCPTK87EMMIKPFS

actions of S100A4 and S100A1 on normal and metastatic phenotypes. Oncogene. 2005; 24: 1445±1454. https://doi.org/10.1038/sj.onc.1208291

國際替代計量

S100A4蛋白可干擾S100A1蛋白和the RAGE V domain結合抑制細胞增生

全文下載

主題瀏覽