HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Thioredoxin and Cell Membrane Protrusions

Thioredoxin reductases (TrxRs) enable thioredoxins to carry out a wide range of cellular functions, including oxidative stress protection, DNA precursor synthesis, and transcriptional regulation, by converting the thioredoxin active site from a disulfide to dithiol. In humans, three genes encode TrxRs, although extensive splicing results in an abundance of protein isoforms. One such variant, referred as TrxR1_v3, is particularly odd since it has an atypical active site without any classical glutaredoxin activity.

TrxR1_v3 co-localizes with actin and tubulin.

In this Paper of the Week, Pascal Dammeyer and colleagues have uncovered the unusual role of this v3 isoform, which is predominantly expressed in Leydig cells of the testes and a few other tissues. Using green fluorescent protein (GFP) fusions with either full-length v3 or just the glutaredoxin domain, they found that this isoform localizes in distinct sites close to the cell membrane in proximity to actin and tubulin. Subsequently, this protein can foster actin and tubulin polymerization to rapidly induce protrusions in the cell membrane. These results showcase the third splice variant of TrxR1, which features a restricted expression pattern and non-standard activity, as a uniquely specialized thioredoxin reductase, and in turn they add a new layer of complexity to the thioredoxin family.

FOOTNOTES

See referenced article, J. Biol. Chem. 2008, 283, 2814-2821

[More Papers of the Week]