Cloning of ABCA17, a novel rodent sperm-specific ABC (ATP-binding cassette) transporter that regulates intracellular lipid metabolism
Cloning of ABCA17, a novel rodent sperm-specific ABC (ATP-binding cassette) transporter that regulates intracellular lipid metabolism
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DOI：
10.1042/bj20050159
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发表时间：
2005-07-15
影响因子：
4.1
通讯作者：
Inagaki, N
中科院分区：
文献类型：
--
作者：
Ban, N;Sasaki, M;Inagaki, N
ABC（ATP结合盒）转运蛋白超家族的A亚类具有区别于其他ABC转运蛋白的结构特征，并被认为参与内源性脂质的跨膜转运。在这里，我们克隆了小鼠和大鼠全长cDNA的ABCA17，一种新的ABC转运蛋白属于A亚类。小鼠和大鼠ABCA 17蛋白分别含有1733和1773个氨基酸残基，氨基酸同源性为87.3%，小鼠ABCA 17与小鼠ABCA 3和海胆ABCA的氨基酸同源性分别为55.3%和36.7%。RNA印迹和实时定量PCR分析表明，ABCA 17 mRNA只在睾丸中表达。睾丸原位杂交结果表明，ABCA 17 mRNA表达于生精小管的生殖细胞，主要是精母细胞。使用特异性抗体的免疫印迹分析表明，ABCA 17是一种200 kDa的蛋白质，免疫组织化学分析表明，该蛋白质在精子的前头部和细长的精子细胞中被检测到。ABCA 17定位于瞬时转染的HEK 293细胞的内质网中。代谢标记分析显示，与未转染的细胞相比，稳定表达ABCA 17的HEK 293细胞中的细胞内酯化脂质，包括胆固醇酯、脂肪酸酯和三酰甘油显著减少。这些结果表明ABCA 17可能在调节精子中的脂质组成中起作用。
The A subclass of the ABC (ATP-binding cassette) transporter superfamily has a structural feature that distinguishes it from other ABC transporters, and is proposed to be involved in the transmembrane transport of endogenous lipids. Here we have cloned mouse and rat full-length cDNAs of ABCA17, a novel ABC transporter belonging to the A subclass. Mouse and rat ABCA17 proteins comprise 1733 and 1773 amino acid residues respectively, having 87.3% amino acid identity; mouse ABCA17 has amino acid identities of 55.3% and 36.7% with mouse ABCA3 and sea urchin ABCA respectively. RNA blot and quantitative real-time PCR analyses showed that ABCA17 mRNA is expressed exclusively in the testis. Examination of testis by in situ hybridization showed that ABCA17 mRNA is expressed in germ cells, mainly spermatocytes, in the seminiferous tubule. Immunoblot analysis using a specific antibody showed that ABCA17 is a protein of 200 kDa, and immunohistochemical analysis demonstrated that the protein is detected in the anterior head of sperm and elongated spermatids. ABCA17 was localized in the endoplasmic reticulum in transiently transfected HEK293 cells. Metabolic labelling analysis showed that intracellular esterified lipids, including cholesteryl esters, fatty acid esters and triacylglycerols, were significantly decreased in HEK293 cells stably expressing ABCA17 compared with untransfected cells. These results suggest that ABCA17 may play a role in regulating lipid composition in sperm.