该基因编码的蛋白属于吡啶核苷酸二硫氧化还原酶家族，是硫氧还蛋白（Trx）系统的成员。在哺乳动物中发现三个硫氧还蛋白还原酶（TrxR）同工酶。TrxRS是含硒半胱氨酸的黄素酶，它减少硫氧还蛋白，以及其他底物，并在氧化还原稳定中起关键作用。该基因编码一种广泛表达的细胞溶质形式的trxr，其在活性部位起着含有fad和硒代半胱氨酸（sec）的同二聚体的作用。sec由uga密码子编码，该密码子通常表示翻译终止。硒蛋白mRNAs的3’UTRs包含一个保守的茎环结构，即Sec插入序列（Sec is）元素，这对于将UGA识别为Sec密码子而不是停止信号是必要的选择性剪接，主要是在5’端，导致转录变体编码相同或不同的异构体，包括在睾丸中主要表达的谷胱甘肽氧合酶异构体。[由RefSeq提供，2017年5月]
The protein encoded by this gene belongs to the pyridine nucleotide-disulfide oxidoreductase family, and is a member of the thioredoxin (Trx) system. Three thioredoxin reductase (TrxR) isozymes are found in mammals. TrxRs are selenocysteine-containing flavoenzymes, which reduce thioredoxins, as well as other substrates, and play a key role in redox homoeostasis. This gene encodes an ubiquitously expressed, cytosolic form of TrxR, which functions as a homodimer containing FAD, and selenocysteine (Sec) at the active site. Sec is encoded by UGA codon that normally signals translation termination. The 3' UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, the Sec insertion sequence (SECIS) element, which is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. Alternative splicing, primarily at the 5' end, results in transcript variants encoding same or different isoforms, including a glutaredoxin-containing isoform that is predominantly expressed in testis. [provided by RefSeq, May 2017]