| Abstract | A cDNA clone, pCHS62, was isolated using poly(A)-rich RNA from heat-shocked Chlamydomonas reinhardtii cells. The clone has a length of 1.1 kb and codes for the complete heat-shock protein which was reported to be associated with the grana region of the thylakoid membranes and ascribes protection against photoinhibition during heat-shock. An expression vector prepared in the pUC19 plasmid was used to obtain a fusion protein against which rabbit polyclonal antibodies have been raised. The antibodies react specifically with the heat-shock protein of 22 kDa synthesized in vivo during heat-shock, which is localized in the grana thylakoids, with the in vitro translated product using poly(A)-rich RNA from heat-treated cells as well as with the hybrid release translation product of the pCHS62 clone. The clone was sequenced. It contains a 5' region consisting of 85 nucleotides, an open reading frame of 471 nucleotides and a non-coding 3' region of 600 nucleotides. Northern hybridization indicates a length of 1.7 kb for the messenger RNA of heat-shock protein 22. Analysis of similarity between the derived amino acid sequence of this protein and other heat-shock proteins demonstrates that this protein belongs to the small-molecular-mass plant heat-shock protein family and also shows similarities with animal heat-shock proteins including the presence of a short region possessing similarity with bovine alpha-crystalline as reported for other heat-shock proteins. The molecular mass of the protein as determined from the sequence is 16.8 kDa. Despite its localization in the chloroplast membranes, it does not seem to include a transit peptide sequence, in agreement with previous data. The sequence contains only a short hydrophobic region compatible with its previously reported localization as a thylakoid extrinsic protein. |
| Authors | B Grimm, D Ish-Shalom, D Even, H Glaczinski, P Ottersbach, I Ohad, K Kloppstech
(Affiliation: Institut für Botanik, Universität Hannover, Federal Republic of Germany.)
|
| Journal | European journal of biochemistry / FEBS
(Eur J Biochem)
Vol. 182
Issue 3
Pg. 539-46
(Jul 1 1989)
ISSN: 0014-2956 GERMANY, WEST |
| PMID | 2473899
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
| Chemical References |
- Heat-Shock Proteins
- RNA, Messenger
- Poly A
- RNA
- DNA
|
| Topics |
- Amino Acid Sequence
- Base Sequence
- Cell Nucleus
(metabolism)
- Chlamydomonas
(genetics)
- Chloroplasts
(metabolism)
- Cloning, Molecular
- DNA
(isolation & purification)
- Genetic Code
- Heat-Shock Proteins
(genetics, isolation & purification, metabolism)
- Molecular Sequence Data
- Nucleic Acid Hybridization
- Plasmids
- Poly A
(isolation & purification)
- RNA
(isolation & purification)
- RNA, Messenger
(isolation & purification)
- Transcription, Genetic
|
