Mammalian Selenocysteine Lyase Is Involved in Selenoprotein Biosynthesis

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Author(s)

Abstract

Selenocysteine lyase (SCL) catalyzes the decomposition of <small>L</small>-selenocysteine to yield <small>L</small>-alanine and selenium by acting exclusively on l-selenocysteine. The X-ray structural analysis of rat SCL has demonstrated how SCL discriminates <small>L</small>-selenocysteine from <small>L</small>-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 <sup>75</sup>Se-labeling efficiency of selenoproteins with <sup>75</sup>Se-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.

Journal

  • Journal of Nutritional Science and Vitaminology

    Journal of Nutritional Science and Vitaminology 57(4), 298-305, 2011

    Center for Academic Publications Japan

Codes

  • NII Article ID (NAID)
    130001373002
  • NII NACSIS-CAT ID (NCID)
    AA00703822
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    0301-4800
  • NDL Article ID
    11218405
  • NDL Source Classification
    ZR2(科学技術--生物学--生化学)
  • NDL Call No.
    Z53-B484
  • Data Source
    CJPref  NDL  IR  J-STAGE 
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