@article { ISI:000271552400019,
	title = {Conformational characterization of human eukaryotic initiation factor 2 alpha: a single tryptophan protein},
	journal = {Biochemical and Biophysical Research Communications},
	volume = {390},
	number = {2},
	year = {2009},
	month = {DEC},
	pages = {273-279},
	publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE},
	address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA},
	abstract = {<p>The alpha-subunit of the human eukaryotic initiation factor 2 (heIF2 alpha), a GTP binding protein, plays a major role in the initiation of protein synthesis. During various cytoplasmic stresses, eIF2 alpha gets phosphorylated by eIF2 alpha-specific kinases resulting in inhibition of protein synthesis. The cloned and over expressed heIF2 alpha, a protein with a single tryptophan (trp) residue was examined for its conformational characteristics using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic dye binding. The steady-state fluorescence spectrum, fluorescence lifetimes (tau(1) = 1.13 ns and tau(2) = 4.74 ns) and solute quenching studies revealed the presence of trp conformers in hydrophobic and differential polar environment at any given time. Estimation of the alpha-helix and beta-sheet content showed: (i) more compact structure at pH 2.0, (ii) distorted alpha-helix and rearranged beta-sheet in presence of 4 M guanidine hydrochloride and (iii) retention of more than 50\% ordered structure at 95 degrees C. Hydrophobic dye binding to the protein with loosened tertiary structure was observed at pH 2.0 indicating the existence of a molten globule-like structure. These observations indicate the inherent structural stability of the protein under various denaturing conditions. (C) 2009 Elsevier Inc. All rights reserved.</p>},
	keywords = {Circular dichroism, heIF2 alpha, K562 cells, Molten globule, Steady-state and time-resolved fluorescence},
	issn = {0006-291X},
	doi = {10.1016/j.bbrc.2009.09.106},
	author = {Sreejith, R. K. and Yadav, Viveka Nand and Varshney, Nishant K. and Berwal, Sunil K. and Suresh, C. G. and Gaikwad, Sushama M. and Pal, Jayanta K.}
}
@article {45416,
	title = {Activation of HRI is mediated by Hsp90 during stress through modulation of the HRI-Hsp90 complex},
	journal = {International Journal of Biological Macromolecules},
	volume = {118},
	year = {2018},
	month = {OCT},
	pages = {1604-1613},
	type = {Article},
	abstract = {Heme Regulated Inhibitor (HRI) is known to get activated in various stresses such as heme deficiency, heat shock, heavy metal toxicity etc. Heat shock protein 90 (Hsp90), a ubiquitous cytoplasmic protein interacts with HRI in order to regulate protein synthesis. However, it still remains to establish this interaction of HRI and Hsp90 at cellular levels and how this modulation of HRI activity is mediated by Hsp90 during stress. In the present report, using co-immunoprecipitation analysis we show that HRI interacts with Hsp90 and this association is independent of other co-chaperones in in vitro conditions. Further, analysis using truncated domains of HRI revealed that the K1 subdomain is essential for HRI - Hsp90 complex formation. Our in silico protein - protein interaction studies also indicated interaction of Hsp90 with K1 subdomain of HRI. Mammalian two hybrid assay validated this HRI - Hsp90 interaction at cellular levels. When the in vitro kinase assay was carried out with the co-immunoprecipitated complex of HRI - Hsp90, an increase in the kinase activity was observed resulting elevated levels of eIF2 alpha phosphorylation upon heavy metal stress and heat shock. Thus, our results clearly indicate modulation of HRI kinase activity with simultaneous Hsp90 association under stress conditions. (C) 2018 Elsevier B.V. All rights reserved.},
	issn = { 0141-8130},
	doi = {10.1016/j.ijbiomac.2018.06.204},
	author = {Berwal, Sunil K. and Bhatia, Varsha and Bendre, Arneya and Suresh, C. G. and Chatterjee, Sangeeta and Pal, Jayanta K.}
}
