MACF1的生物信息学分析及细胞定位

目的：了解微管微丝交联因子1（MACF1）的结构与功能．方法：采用生物信息学软件对MACF1结构、功能及亚细胞定位进行分析，并利用分子模拟软件对MACF1空间结构进行了模拟，同时采用免疫荧光显微术及共聚焦激光扫描显微术（CLSM）对生物信息学分析的部分结果进行了验证．结果：MACF1由5430氨基酸组成，M，约为620×10^3，主要定位于胞质及细胞骨架．MACF1结构中包含1个ABD、37个血影蛋白重复单元、1个SH3结构域、2个EF手臂钙结合位点结构域、1个生长捕获特异蛋白2结构域等基序，并包含4个序列谱及5个序列模式．MACF1的德温特人藏号为Q9UPN3，MACF1包括4个亚型即MACF1／2／3／5，主要功能可能是将微丝、微管与其它骨架蛋白交联．同源模建结果表明，MACF1与α-辅肌动蛋白的ABD结构域一级序列的同源性为50．2％．免疫荧光显微术及CLSM结果表明，MACF1主要分布与细胞质，且与微丝、微管骨架部分共定位．结论：MACF1是一种大分子量的骨架交联蛋白，主要定位于细胞质，且与微丝、微管骨架部分共定位，MACF1结构功能可能与Ot辅肌动蛋白有一定的相似性．

Bioinformatics analysis and cellular localization of microtubule actin cross-linking factor1

AIM ： To analyze the structure and function of microtubule actin cross-linking factor 1 （MACF1）. METHODS： Several bioinformaties softwares were used to predict and analyze the structure, function, location of MACF1. Molecular simulation softwares were employed to simulate the 3-D structure of MACF1. Immunofluorescenee microscopy and confocal laser scanning microscopy （CLSM） were utilized to verify the subeellular location of MACF1. RESULTS： MACF1 was a large protein （M, 620 ± 10^3） and contained 5430 amino acids. MACF1 was widely expressed in many tissues and mainly located in cytoplasm and cytoskeleton. MACF1 contained an N-terminal actin binding domain （ABD） , 37 spectrin repeats, 1 SH3 domain, 2 EF-hand calponin binding domain and 1 growth arrest specific protein 2 （GAS2） domain. There were also 4 profiles and 5 patterns in MACF1 sequence. The primary accession number of MACF1 was Q9UPN3 and there were 4 isoforms, namely MACF 1/2/3/5. The main role of MACF1 was to associate aetin and microtubule with other eytoskeletal proteins. The homology of primary sequence between MACF1 and α-actinin was 50. 2%. Immunofluorescence microscopy and CLSM showed that MACF1 was widely expressed in cytoplasm and colocalized with aetin microfilament and microtubule. CONCLUSION： MACF1, as a large cytoskeletal crosslinking protein, is widely expressed in many kinds of cells and mainly locates in cytoplasm. The structure and function of MACF1 may have some similarity to that of α-actinin.