Kutta, Roger J. and Hofinger, Edith S. A. and Preuss, Hendrik and Bernhardt, Guenther and Dick, Bernhard (2008) Blue-light induced interaction of LOV domains from Chlamydomonas reinhardtii. CHEMBIOCHEM, 9 (12). pp. 1931-1938. ISSN 1439-4227, 1439-7633
Full text not available from this repository. (Request a copy)Abstract
The phototropin from Chlamydomonas reinhardtii is a 120 kDa blue light receptor that plays a key role in gametogenesis of this green alga. It comprises two light-sensing domains termed LOV1 and LOV2 (light oxygen and voltage) and a serine/threonine kinase domain. The post-translationally incorporated chromophore is flavin mononucleotide (FMN). Upon absorption of blue light, LOV domains undergo a photocycle that activates a Ser/Thr kinase. The mechanism of this activation is still unknown. We studied the oligomerization of the recombinant LOV1 domain (amino acids 16-133) of C. reinhardtii by means of UV/Vis spectroscopy, size exlusion chromatography (SEC) and chemical cross linking with glutardialdehyde. The thermal back reaction of LOV1 from the signaling state to the dark state as monitored by UV/Vis spectroscopy after an intensive blue light pulse could not be explained by a monoexponential model, although the spectra did not indicate the presence of an additional species. Therefore, we investigated the quaternary structure of the LOV1 domain by size-exlusion chromatography in the dark. This revealed an equilibrium between dimers and higher oligomers (M-w > 200 kDa) under native conditions. No monomers were detected by SEC. However, by analysis of the equilibrium by cross-linking of the protein with glutaraldehyde and subsequent SDS-PAGE, monomers and dimers were identified. Exposure to LOV1 to blue light resulted in a decrease in the monomer/dimer ratio. A model is presented that accounts for a blue-light driven change in the quaternary structure of the LOV1 domain and gives hints to the molecular basis of light activation and regulation in LOV-containing proteins.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PHOTORECEPTOR PHOTOTROPIN; INDUCED PHOSPHORYLATION; FLAVIN MONONUCLEOTIDE; ARABIDOPSIS NPH1; MOLECULAR SWITCH; BINDING DOMAINS; CROSS-LINKING; PROTEIN; DIMERIZATION; RECEPTORS; Chlamydomonas reinhardtii; photochemistry; photoreceptors; phototropin; protein structures |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 600 Technology > 615 Pharmacy |
| Divisions: | Chemistry and Pharmacy > Institute of Pharmacy Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Bernhard Dick |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 26 Oct 2020 13:53 |
| Last Modified: | 26 Oct 2020 13:53 |
| URI: | https://pred.uni-regensburg.de/id/eprint/30482 |
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