真核生物糖酵解终产物―丙酮酸进入线粒体并转化为乙酰-CoA，乙酰-CoA必须转运到细胞溶胶中，才能用于脂质合成。因此，乙酰-CoA以柠檬酸为载体从线粒体转运到细胞溶胶的途径是影响脂质合成的关键因素之一。本课题组前期研究解析了卷枝毛霉WJ11的基因组，发现卷枝毛霉存在三个线粒体柠檬酸转运相关蛋白质：三羧酸转运体、柠檬酸转运体、苹果酸转运体。前期研究发现苹果酸转运体调控苹果酸的转运，并直接影响卷枝毛霉脂质积累，但是该转运体如何促进线粒体柠檬酸向细胞溶胶转运的机制尚不明确，对其它两种转运体也未曾研究。本课题将通过基因工程、分子生物学、以及酶学分析等技术对卷枝毛霉线粒体柠檬酸转运体系进行功能分析，对该转运体系在脂质积累中的作用和相关机制进行深入研究。本课题的研究将提升我们对产脂真菌线粒体柠檬酸转出及其调控脂质积累机制的认识，为进一步深入解析线粒体柠檬酸转运关键蛋白质的三维结构与功能奠定基础。

As the end product of glycolysis, pyruvate is converted to acetyl-CoA when it is transported into the mitochondria of eukaryotic cells. However lipid synthesis happens in the cytosol, so only when acetyl-CoA is transported into the cytosol, then it can be used for lipid synthesis. Therefore, using citrate as the carrier, transport of acetyl-CoA from the mitochondria to the cytosol play a key role in regulating lipid biosynthesis. We have previously sequenced and analyzed the genome of Mucor circinelloides WJ11, and found that there are three related transporters for mitochondrial citrate transport: tricarboxylate transporter, citrate transporter and malate transporter. Our preliminary work on the malate transporter in Mucor cirnelloides CBS277.49 has shown that this transporter regulates the influx of malate into the mitochondria and lipid accumulation. However, the molecular mechanism of increasing citrate efflux from the mitochondria by malate transporter is unclear. In addition, no investigation has been carried out with the other two transporters. So, in this project, the identity and functions of the mitochondrial citrate transport system, and its role in lipid accumulation in this fungus will be fully investigated using genetic engineering,molecular biology and enzymological analysis. This work will provide new insights into the mechanism of mitochondrial citrate efflux and its association with lipid accumulation in oleaginous fungi, and lay a foundation for further three dimensional structure and function studies of key mitochondrial citrate transport proteins.