A new type of flexible CP12 protein in the marine diatom Thalassiosira pseudonana - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Cell Communication and Signaling Année : 2021

A new type of flexible CP12 protein in the marine diatom Thalassiosira pseudonana

Résumé

Background: CP12 is a small chloroplast protein that is widespread in various photosynthetic organisms and is an actor of the redox signaling pathway involved in the regulation of the Calvin Benson Bassham (CBB) cycle. The gene encoding this protein is conserved in many diatoms, but the protein has been overlooked in these organisms, despite their ecological importance and their complex and still enigmatic evolutionary background. Methods: A combination of biochemical, bioinformatics and biophysical methods including electrospray ionizationmass spectrometry, circular dichroism, nuclear magnetic resonance spectroscopy and small X ray scattering, was used to characterize a diatom CP12. Results: Here, we demonstrate that CP12 is expressed in the marine diatom Thalassiosira pseudonana constitutively in dark-treated and in continuous light-treated cells as well as in all growth phases. This CP12 similarly to its homologues in other species has some features of intrinsically disorder protein family: it behaves abnormally under gel electrophoresis and size exclusion chromatography, has a high net charge and a bias amino acid composition. By contrast, unlike other known CP12 proteins that are monomers, this protein is a dimer as suggested by native electrospray ionization-mass spectrometry and small angle X-ray scattering. In addition, small angle X-ray scattering revealed that this CP12 is an elongated cylinder with kinks. Circular dichroism spectra indicated that CP12 has a high content of α-helices, and nuclear magnetic resonance spectroscopy suggested that these helices are unstable and dynamic within a millisecond timescale. Together with in silico predictions, these results suggest that T. pseudonana CP12 has both coiled coil and disordered regions. Conclusions: These findings bring new insights into the large family of dynamic proteins containing disordered regions, thus increasing the diversity of known CP12 proteins. As it is a protein that is more abundant in many stresses, it is not devoted to one metabolism and in particular, it is not specific to carbon metabolism. This raises questions about the role of this protein in addition to the well-established regulation of the CBB cycle.
Fichier principal
Vignette du fichier
ThapsCP12_Hui_2021.pdf (1.76 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03194815 , version 1 (09-04-2021)

Identifiants

Citer

Hui Shao, Wenmin Huang, Luisana Avilan, Véronique Receveur-Bréchot, Carine Puppo, et al.. A new type of flexible CP12 protein in the marine diatom Thalassiosira pseudonana. Cell Communication and Signaling, 2021, 19 (1), ⟨10.1186/s12964-021-00718-x⟩. ⟨hal-03194815⟩

Collections

CNRS UNIV-AMU
39 Consultations
48 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More