Genomic organisation and alternative splicing of mouse and human thioredoxin reductase 1 genes

Simone A Osborne,Kathryn F Tonissen

doi:10.1186/1471-2164-2-10

Abstract

BackgroundThioredoxin reductase (TR) is a redox active protein involved in many cellular processes as part of the thioredoxin system. Presently there are three recognised forms of mammalian thioredoxin reductase designated as TR1, TR3 and TGR, that represent the cytosolic, mitochondrial and novel forms respectively. In this study we elucidated the genomic organisation of the mouse (Txnrd1) and human thioredoxin reductase 1 genes (TXNRD1) through library screening, restriction mapping and database mining.ResultsThe human TXNRD1 gene spans 100 kb of genomic DNA organised into 16 exons and the mouse Txnrd1 gene has a similar exon/intron arrangement. We also analysed the alternative splicing patterns displayed by the mouse and human thioredoxin reductase 1 genes and mapped the different mRNA isoforms with respect to genomic organisation. These isoforms differ at the 5' end and encode putative proteins of different molecular mass. Genomic DNA sequences upstream of mouse exon 1 were compared to the human promoter to identify conserved elements.ConclusionsThe human and mouse thioredoxin reductase 1 gene organisation is highly conserved and both genes exhibit alternative splicing at the 5' end. The mouse and human promoters share some conserved sequences.

Highlights

Thioredoxin reductase (TR) is a redox active protein involved in many cellular processes as part of the thioredoxin system
We focus upon the cytosolic form of mouse thioredoxin reductase and human thioredoxin reductase
Mouse Txnrd1 genomic organisation To determine the genomic structure of the mouse Txnrd1 gene we initially screened a mouse genomic DNA library using a mouse Txnrd1 cDNA fragment as a probe

Summary

Introduction

Thioredoxin reductase (TR) is a redox active protein involved in many cellular processes as part of the thioredoxin system. There are three recognised forms of mammalian thioredoxin reductase designated as TR1, TR3 and TGR, that represent the cytosolic, mitochondrial and novel forms respectively. The thioredoxin system is comprised of thioredoxin (Trx) and thioredoxin reductase (TR) and plays an important role in maintaining the redox state of the cell [1]. This system is involved in many cellular functions including synthesis of deoxyribonucleotides [2], redox control of transcription factors [3], protection against oxidative stress [4], cell growth and cancer [5].

Methods

Results

Conclusion