Selenoprotein W accumulates primarily in primate skeletal muscle, heart, brain and tongue

The human selenoprotein W coding region with the selenocysteine codon (TGA) changed to a cysteine codon (TGT) was fused to six histidine codons (at it s 3' end), cloned into a prokaryotic expression vector (pTrc99a), and the c orresponding mutated selenoprotein W was expressed in bacteria. The protein was purified by Ni-NTA agarose column and reverse phase HPLC. Polyclonal a ntibodies raised against this protein were used in Western blots to determi ne tissue distribution of selenoprotein W from rhesus monkeys fed a commerc ial chow. Selenoprotein W was found in several tissues with highest amounts in skeletal muscle and heart (muscle 6 fold greater than liver) and lowest levels in liver, but selenium concentrations were highest in kidneys (10 f old greater than muscle) and lowest in skeletal muscle. Northern blots usin g a human selenoprotein W cDNA probe indicated that mRNA levels were highes t in monkey skeletal muscle and heart (2-2.5 fold greater than in liver), w hich is similar to the pattern found with a human multiple tissue Northern blot. However, as in the monkey, selenium concentrations were highest in hu man kidney and lowest in skeletal muscle and heart. Thus, selenoprotein W p rotein levels correlated with selenoprotein W mRNA levels but not with tiss ue selenium concentrations.