Intrinsic disorder of Drosophila melanogaster hormone receptor 38 N-terminal domain.
Drosophila hormone receptor 38 (dHR38), an ortholog of the vertebrate NR4A subclass of nuclear receptors, responds to ecdysteroids, which mediate developmental transitions during the Drosophila life cycle. However, this response is independent of the ecdysteroid receptor, and it does not involve binding of ecdysteroids to dHR38. It has been suggested that ecdysteroids may indirectly activate dHR38, perhaps by recruiting specific proteins. There have been recent reports pointing out the decisive role that nuclear receptor N-terminal domains (NTDs) have in protein-protein interactions that are important for regulation of gene expression. It is reasonable to assume that dHR38-NTD may also be involved in some protein-protein interactions that are critical for the ecdysteroid signaling pathway. To facilitate the exploration of the molecular basis of these interactions, we developed and optimized a protocol for the efficient expression and purification of the recombinant dHR38-NTD. Using a diverse array of biochemical and biophysical methods, we carried out the first structural characterization of dHR38-NTD. The results of our study indicate that dHR38-NTD exhibits a characteristic reminiscent of pre-molten globule-like intrinsically disordered proteins existing in a partially unfolded conformation with regions of secondary structures. The dHR38-NTD structure, which apparently comprises some local, ordered, tertiary structure clusters, is pliable and can adopt more ordered conformations in response to changes in environmental conditions. Thus, dHR38-NTD, which exhibits the structural and functional characteristic of a pre-molten globule-like intrinsically disordered protein, could serve as a platform for multiple protein-protein interactions, possibly including interactions with proteins involved in an unusual ecdysteroid signaling pathway.
Department of Biochemistry, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370, Poland.
Agnieszka
A
Dziedzic-Letka
Grzegorz
G
Rymarczyk
Tomasz M
TM
Kapłon
Andrzej
A
Górecki
Agnieszka
A
Szamborska-Gbur
Magdalena
M
Wojtas
Piotr
P
Dobryszycki
Andrzej
A
Ożyhar
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003198:Computer Simulation; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D005470:Fluorometry; D019791:Guanidine / Q000737:chemistry; D057446:Hydrodynamics; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D058767:Protein Unfolding; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D014270:Trifluoroethanol / Q000737:chemistry
D029721:Drosophila Proteins; C095176:Hr38 protein, Drosophila; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D014270:Trifluoroethanol; D019791:Guanidine