Glutaredoxin-3 is a protein that in humans is encoded by the GLRX3 gene.

This gene encodes a member of the glutaredoxin family. Glutaredoxins are oxidoreductase enzymes that reduce a variety of substrates using glutathione as a cofactor. The encoded protein binds to and modulates the function of protein kinase C theta. The encoded protein may also inhibit apoptosis and play a role in cellular growth, and the expression of this gene may be a marker for cancer. Pseudogenes of this gene are located on the short arm of chromosomes 6 and 9. Alternatively spliced transcript variants have been observed for this gene. [provided by RefSeq, Dec 2010].
Function: Critical negative regulator of cardiac hypertrophy and a positive inotropic regulator (By similarity). May play a role in regulating the function of the thioredoxin system. Does not posses any thyoredoxin activity since it lacks the conserved motif that is essential for catalytic activity.