Background
Selenoproteins (25 genes in human) co-translationally incorporate selenocysteine using a UGA codon, normally used as a stop signal. The human selenoproteome is primarily regulated by selenium bioavailability with a tissue-specific hierarchy.
Conclusions
We characterized that selenoprotein hierarchy is cell-line specific with conserved features. This analysis should be done prior to any experiments in a novel cell line. General significance: We reported a strategy based on complementary methods to evaluate selenoproteome regulation in human cells in culture.
Methods
We investigated the hierarchy of selenoprotein expression in response to selenium concentration variation in four cell lines originating from kidney (HEK293, immortalized), prostate (LNCaP, cancer), skin (HaCaT, immortalized) and liver (HepG2, cancer), using complementary analytical methods. We performed (i) enzymatic activity, (ii) RT-qPCR, (iii) immuno-detection, (iv) selenium-specific mass spectrometric detection after non-radioactive 76Se labeling of selenoproteins, and (v) luciferase-based reporter constructs in various cell extracts.
Results
We characterized cell-line specific alterations of the selenoproteome in response to selenium variation that, in most of the cases, resulted from a translational control of gene expression. We established that UGA-selenocysteine recoding efficiency, which depends on the nature of the SECIS element, dictates the response to selenium variation. Conclusions: We characterized that selenoprotein hierarchy is cell-line specific with conserved features. This analysis should be done prior to any experiments in a novel cell line. General significance: We reported a strategy based on complementary methods to evaluate selenoproteome regulation in human cells in culture.
Significance
We reported a strategy based on complementary methods to evaluate selenoproteome regulation in human cells in culture.