MACF1的生物信息学分析及细胞定位

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

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,Mr约为620×103,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的德温特入藏号为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α辅肌动蛋白有一定的相似性.

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.