Antimalarial drugs with novel modes of action and wide therapeutic potential are needed to pave the way for malaria eradication. Violacein is a natural compound known its biological activity against cancer cells several pathogens, including parasite, Plasmodium falciparum (Pf). Herein, using chemical genomic profiling (CGP), we found that violacein affects protein homeostasis. Mechanistically, ...

Although glycine-rich RNA-binding proteins (GRPs) have been determined to function as RNA chaperones during the cold adaptation process, the structural features relevant to this RNA chaperone activity remain largely unknown. To uncover which structural determinants are necessary for RNA chaperone activity of GRPs, the importance of the N-terminal RNA recognition motif (RRM) and the C-terminal g...

PURPOSE AIPL1 mutations cause the severe inherited blindness Leber congenital amaurosis (LCA). The similarity of AIPL1 to tetratricopeptide repeat (TPR) cochaperones that interact with the chaperone Hsp90 and the ability of AIPL1 to suppress the aggregation of NUB1 fragments in a chaperone-like manner suggest that AIPL1 might function as part of a chaperone heterocomplex facilitating retinal pr...

Chloroplast protein synthesis elongation factor, EF-Tu, has been implicated in heat tolerance in maize. The recombinant precursor of this protein, pre-EF-Tu, has been found to exhibit chaperone activity and protect heat-labile proteins, such as citrate synthase and malate dehydrogenase, from thermal aggregation. Chloroplast EF-Tu is highly conserved and it is possible that the chaperone activit...

AtTDX, a thioredoxin-like plant-specific protein present in Arabidopsis is a thermo-stable and multi-functional enzyme. This enzyme is known to act as a thioredoxin and as a molecular chaperone depending upon its oligomeric status. The present study examines the effects of γ-irradiation on the structural and functional changes of AtTDX. Holdase chaperone activity of AtTDX was increased and reac...

The chaperone activity and biophysical properties of recombinant human aAand aB-crystallins were studied by light scattering and spectroscopic methods. While the chaperone function of aA-crystallin markedly improves with an increase in temperature, the activity of aB homopolymer appears to change very little upon heating. Compared with aB-crystallin, the aA-homopolymer is markedly less active a...

Assembly of the bacterial flagellar filament requires a type III export pathway for ordered delivery of structural subunits from the cytosol to the cell surface. This is facilitated by transient interaction with chaperones that protect subunits and pilot them to dock at the membrane export ATPase complex. We reveal that the essential export protein FliJ has a novel chaperone escort function in ...

JCB • VOLUME 167 • NUMBER 2 • 2004 190 A chaperone feels the heat chaperone is supposed to keep its cool when temperatures get hot. But Syed Rizvi, Laura Mancino, Malini Raghavan (University of Michigan, Ann Arbor, MI), and colleagues show that calreticulin—a glycoprotein chaperone—starts to melt in the heat. The resulting structural changes actually improve its chaperone activity and may also ...

The lipase from Pseudomonas cepacia ATCC 21808 (recently reclassified as Burkholderia cepacia) is widely used by organic chemists for enantioselective synthesis and is manufactured from recombinant P. cepacia harboring on a plasmid the clustered genes for lipase and its chaperone. High levels of expression of inactive lipase (40%) in Escherichia coli were achieved with pCYTEXP1 under the contro...

Sgt1p is a conserved, essential protein required for kinetochore assembly in both yeast and animal cells. Sgt1p has homology to both TPR and p23 domains, sequences often found in proteins that interact with and regulate the molecular chaperone, Hsp90. The presence of these domains and the recent findings that Sgt1p interacts with Hsp90 has led to the speculation that Sgt1p and Hsp90 form a co-c...