Evolution and cellular function of monothiol glutaredoxins: involvement in iron–sulphur cluster assembly

Abstract

A number of bacterial species, mostly proteobacteria, possess monothiol glutaredoxins homologous to the Saccharomyces cerevisiae mitochondrial protein Grx5, which is involved in iron-sulphur cluster synthesis. Phylogenetic profiling is used to predict that bacterial monothiol glutaredoxins also participate in the iron-sulphur cluster (ISC) assembly machinery, because their phylogenetic profiles are similar to the profiles of the bacterial homologues of yeast ISC proteins. High evolutionary cooccurrence is observed between the Grx5 homologues and the homologues of the Yah1 ferredoxin, the scaffold proteins Isa1 and Isa2, the frataxin protein Yfh1 and the Nfu1 protein. This suggests that a specific functional interaction exists between these ISC machinery proteins. Physical interaction analyses using low-definition protein docking predict the formation of strong and specific complexes between Grx5 and several components of the yeast ISC machinery. Two-hybrid analysis has confirmed the in vivo interaction between Grx5 and Isa1. Sequence comparison techniques and cladistics indicate that the other two monothiol glutaredoxins of S. cerevisiae, Grx3 and Grx4, have evolved from the fusion of a thioredoxin gene with a monothiol glutaredoxin gene early in the eukaryotic lineage, leading to differential functional specialization. While bacteria do not contain these chimaeric glutaredoxins, in many eukaryotic species Grx5 and Grx3/4-type monothiol glutaredoxins coexist in the cell.

Glutaredoxins Grx4 and Grx3 of Saccharomyces cerevisiae Play a Role in Actin Dynamics through Their Trx Domains, Which Contributes to Oxidative Stress Resistance

“…This induced substantial and efficient cable formation in both cells growing exponentially and in response to treatment with the oxidant hydrogen peroxide, as is clearly shown and quantified in Fig. 7C and D. Both Trx domains contain a WAD/EPCK sequence that is reminiscent of the authentic active site motif of thioredoxins WCGPCK (45). We therefore raised the question as to whether the function that both Trx domains demonstrate in actin cytoskeleton polarization could have been exerted through the cysteine residues contained in their putative active site motives.…”

“…We have also demonstrated that the role that both Grx3 and Grx4 play in actin cable formation is not the consequence of the intracellular accumulation of iron described in the grx3 grx4 double mutant (39), or of ROS accumulation, which was determined in the absence of Grx3 and Grx4 in this study. Each of the two Grx3 and Grx4 proteins has one thioredoxin domain (Trx), followed by one glutaredoxin domain (Grx) (5,39,45). In a previous study, we demonstrated that each Grx domain of both Grx3 and Grx4 played a role in Aft1 translocation from the nucleus to the cytoplasm.…”

Glutaredoxins Grx3 and Grx4 regulate nuclear localisation of Aft1 and the oxidative stress response inSaccharomyces cerevisiae

“…The vector pTP19 bears the Grx domain of Grx4 constructed in pGBT9 in EcoRI-PstI sites by using GSLOL52 and MMO171. As a control for positive nuclear interaction we used the pair of plasmids pACT2SNF4 and pGBT9SNF1 (see Vilella et al, 2004). And finally pACT2YAK1 and pGBT9GRX5 were used as a negative control for nuclear interaction (Vilella et al, 2004).…”

“…As a control for positive nuclear interaction we used the pair of plasmids pACT2SNF4 and pGBT9SNF1 (see Vilella et al, 2004). And finally pACT2YAK1 and pGBT9GRX5 were used as a negative control for nuclear interaction (Vilella et al, 2004). The plasmid pMM351 is an integrative vector that contains three repetitions of the hemagglutinin (HA) epitope in the C-terminal position and also bears the regulatable tetO 7 promoter.…”

Mono- and Dithiol Glutaredoxins in the Trypanothione-Based Redox Metabolism of Pathogenic Trypanosomes

“…Instead, the capability to coordinate ISCs appears to be a common feature for 1-C-Grxs (16,40,42,43,54,67,89) with yeast Grx7 being, so far, the only known exception (59,60). The latter feature determines an evolutionary conserved and indispensable role of 1-C-Grxs in the biogenesis and assembly of iron-sulfur proteins (11,61) and other cell-specific regulatory functions such as the (in)activation of nuclear transcription factors (35,62,86).…”