期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：2011
卷号：57
期号：4
页码：298-305
DOI：10.3177/jnsv.57.298
出版社：Center for Academic Publications Japan
摘要：Selenocysteine lyase (SCL) catalyzes the decomposition of L -selenocysteine to yield L -alanine and selenium by acting exclusively on l-selenocysteine. The X-ray structural analysis of rat SCL has demonstrated how SCL discriminates L -selenocysteine from L -cysteine on the molecular basis. SCL has been proposed to function in the recycling of the micronutrient selenium from degraded selenoproteins containing selenocysteine residues, but the role of SCL in selenium metabolism in vivo remains unclear. We here demonstrate that the 75Se-labeling efficiency of selenoproteins with 75Se-labeled selenoprotein P (Sepp1) as a selenium source was decreased in HeLa cells transfected with SCL siRNA as compared to the cells transfected with control siRNA. Immunocytochemical analyses showed high SCL expression in kidney and liver cells, where selenocysteine is recovered from selenoproteins. Mature testes of mice exhibited a specific staining pattern of SCL in spermatids that actively produce selenoproteins. However, SCL was weakly expressed in Sertoli cells, which receive Sepp1 and supply selenium to germ cells. These demonstrate that SCL occurs in the cells requiring selenoproteins, probably to recycle selenium derived from selenoproteins such as Sepp1.
