Characterization of rice small heat shock proteins targeted to different cellular organelles

Mani, Nandini and Ramakrishna, Krishnaveni and Suguna, Kaza (2015) Characterization of rice small heat shock proteins targeted to different cellular organelles. In: CELL STRESS & CHAPERONES, 20 (3). pp. 451-460.

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Abstract

Small heat shock proteins (sHSPs) are a family of ATP-independent molecular chaperones which prevent cellular protein aggregation by binding to misfolded proteins. sHSPs form large oligomers that undergo drastic rearrangement/dissociation in order to execute their chaperone activity in protecting substrates from stress. Substrate-binding sites on sHSPs have been predominantly mapped on their intrinsically disordered N-terminal arms. This region is highly variable in sequence and length across species, and has been implicated in both oligomer formation and in mediating chaperone activity. Here, we present our results on the functional and structural characterization of five sHSPs in rice, each differing in their subcellular localisation, viz., cytoplasm, nucleus, chloroplast, mitochondria and peroxisome. We performed activity assays and dynamic light scattering studies to highlight differences in the chaperone activity and quaternary assembly of sHSPs targeted to various organelles. By cloning constructs that differ in the length and sequence of the tag in the N-terminal region, we have probed the sensitivity of sHSP oligomer assembly and chaperone activity to the length and amino acid composition of the N-terminus. In particular, we have shown that the incorporation of an N-terminal tag has significant consequences on sHSP quaternary structure.

Item Type:	Journal Article
Publication:	CELL STRESS & CHAPERONES
Publisher:	SPRINGER
Additional Information:	Copy right for this article belongs to the SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
Keywords:	Small heat shock protein; Oryza sativa; Molecular chaperones; Stress response
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	22 May 2015 07:14
Last Modified:	22 May 2015 07:14
URI:	http://eprints.iisc.ac.in/id/eprint/51551

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