SLC24A5 encodes a trans-golgi network protein with potassium-dependent sodium-calcium exchange activity that regulates human epidermal melanogenesis

被引:110
作者
Ginger, Rebecca S. [1 ]
Askew, Sarah E. [1 ]
Ogborne, Richard M. [1 ]
Wilson, Stephen [1 ]
Ferdinando, Dudley [1 ]
Dadd, Tony [1 ]
Smith, Adrian M. [1 ]
Kazi, Shubana [1 ]
Szerencsei, Robert T. [2 ]
Winkfein, Robert J. [2 ]
Schnetkamp, Paul P. M. [2 ]
Green, Martin R. [1 ]
机构
[1] Unilever Res Labs Colworth, Colworth Sci Parks, Sharnbrook MK44 1LQ, Beds, England
[2] Univ Calgary, Hotchkiss Brain Inst, Dept Phys & Biophys, Calgary, AB T2N 4N1, Canada
关键词
D O I
10.1074/jbc.M707521200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A non-synonymous single nucleotide polymorphism in the human SLC24A5 gene is associated with natural human skin color variation. Multiple sequence alignments predict that this gene encodes a member of the potassium-dependent sodium-calcium exchanger family denoted NCKX5. In cultured human epidermal melanocytes we show using affinity-purified antisera that native human NCKX5 runs as a triplet of similar to 43 kDa on SDS-PAGE and is partially localized to the trans-Golgi network. Removal of the NCKX5 protein through small interfering RNA-mediated knockdown disrupts melanogenesis in human and murine melanocytes, causing a significant reduction in melanin pigment production. Using a heterologous expression system, we confirm for the first time that NCKX5 possesses the predicted exchanger activity. Site-directed mutagenesis of NCKX5 and NCKX2 in this system reveals that the non-synonymous single nucleotide polymorphism in SLC24A5 alters a residue that is important for NCKX5 and NCKX2 activity. We suggest that NCKX5 directly regulates human epidermal melanogenesis and natural skin color through its intracellular potassium-dependent exchanger activity.
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收藏
页码:5486 / 5495
页数:10
相关论文
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