The 23-kDa light-stress-regulated heat-shock protein of Chenopodium rubrum L. is located in the mitochondria

authored by

Karsten Debel, Walter D. Sierralta, Hans-Peter Braun, Udo Schmitz, Klaus Kloppstech

Abstract

The 23-kDa nuclear-encoded heat-shock protein (HSP) of Chenopodium rubrum L. is regulated by light at tile posttranslational level. Higher light intensities are more effective in inducing the accumulation of the mature protein under heat-shock conditions. Based on this and other properties the protein was considered to belong to the group of small chloroplastic HSPs. However, we have now obtained the following evidence that this 23-kDa HSP is localized in the mitochondria: (i) Immunogold-labelled protein was almost exclusively restricted to the mitochondria in electron microscope thin sections. (ii) rising purified, isolated mitochondria from potato tubers the in-vitro-synthesized translation product of 31 kDa was readily transported into mitochondria where it was processed to the 23-kDa product. (iii) The protein could be detected by Western blotting in a preparation of washed mitochondria of Chenopodium, while under the same conditions no signal could be obtained in a preparation of isolated chloroplasts. (iv) Finally, sequence comparison with the published sequences of mitochondrial proteins by Lenne et al. (1995, Biochem J 311:805 813)and LaFayette et al. (1996, Plant Mol Biol 31):159 169) showed clearly that the 23-kDa protein is considerably more similar to these two proteins than to the group of plastid small HSPs. From these data we infer that mitochondria are involved in the response of the plants to high light stress under heat-shock conditions.

Organisation(s)

Section Plant Molecular Biology and Plant Proteomics

External Organisation(s)

Max-Planck-Institut für experimentelle Endokrinologie

Type

Article

Journal

Planta

Volume

201

Pages

326-333

No. of pages

8

ISSN

0032-0935

Publication date

03.1997

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Genetics, Plant Science

Electronic version(s)

https://doi.org/10.1007/s004250050074 (Access: Unknown)