TY - JOUR
T1 - Domain organization in plant blue-light receptor phototropin2 of arabidopsis thaliana studied by small-angle x-ray scattering
AU - Nakasako, Masayoshi
AU - Oide, Mao
AU - Takayama, Yuki
AU - Oroguchi, Tomotaka
AU - Okajima, Koji
N1 - Funding Information:
Funding: This study was supported by grants from the Japanese Society for the Promotion of Science to M.N. (Nos. jp16H02218, jp22244054, jp22018027, jp20050030, and jp1920402), T.O (Nos. 26800227 and 17H04854), and K.O. (No. 15K18559), and by grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan to M.N. (Nos. jp15076210, jp15H01647, 17H05891, jp25120725, and jp23120525) and T.O. (No. 26104535). The SAXS experiments were performed with the approval of the RIKEN Harima Institute (proposal Nos. 2011007, 20140018, and 20150021).
Funding Information:
This study was supported by grants from the Japanese Society for the Promotion of Science to M.N. (Nos. jp16H02218, jp22244054, jp22018027, jp20050030, and jp1920402), T.O (Nos. 26800227 and 17H04854), and K.O. (No. 15K18559), and by grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan to M.N. (Nos. jp15076210, jp15H01647, 17H05891, jp25120725, and jp23120525) and T.O. (No. 26104535). The SAXS experiments were performed with the approval of the RIKEN Harima Institute (proposal Nos. 2011007, 20140018, and 20150021). Acknowledgments: We are grateful to Katsuaki Inoue and Takaaji Hikima for their help in SAXS experiments, and also Satoru Tokutomi of Osaka Prefecture University for his encouragement and support in the preliminary stage of this study. SAXS experiments were performed at BL40B2 with the approval of the Japan Synchrotron Radiation Institute and BL45XU with the approval of the RIKEN Harima Institute.
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/9/2
Y1 - 2020/9/2
N2 - Phototropin2 (phot2) is a blue-light (BL) receptor protein that regulates the BL-dependent activities of plants for efficient photosynthesis. Phot2 is composed of two light-oxygen-voltage sensing domains (LOV1 and LOV2) to absorb BL, and a kinase domain. Photo-activated LOV domains, especially LOV2, play a major role in photo-dependent increase in the phosphorylation activity of the kinase domain. The atomic details of the overall structure of phot2 and the intramolecular mechanism to convert BL energy to a phosphorylation signal remain unknown. We performed structural studies on the LOV fragments LOV1, LOV2, LOV2-linker, and LOV2-kinase, and full-length phot2, using small-angle X-ray scattering (SAXS). The aim of the study was to understand structural changes under BL irradiation and discuss the molecular mechanism that enhance the phosphorylation activity under BL. SAXS is a suitable technique for visualizing molecular structures of proteins in solution at low resolution and is advantageous for monitoring their structural changes in the presence of external physical and/or chemical stimuli. Structural parameters and molecular models of the recombinant specimens were obtained from SAXS profiles in the dark, under BL irradiation, and after dark reversion. LOV1, LOV2, and LOV2-linker fragments displayed minimal structural changes. However, BL-induced rearrangements of functional domains were noted for LOV2-kinase and full-length phot2. Based on the molecular model together with the absorption measurements and biochemical assays, we discuss the intramolecular interactions and domain motions necessary for BL-enhanced phosphorylation activity of phot2.
AB - Phototropin2 (phot2) is a blue-light (BL) receptor protein that regulates the BL-dependent activities of plants for efficient photosynthesis. Phot2 is composed of two light-oxygen-voltage sensing domains (LOV1 and LOV2) to absorb BL, and a kinase domain. Photo-activated LOV domains, especially LOV2, play a major role in photo-dependent increase in the phosphorylation activity of the kinase domain. The atomic details of the overall structure of phot2 and the intramolecular mechanism to convert BL energy to a phosphorylation signal remain unknown. We performed structural studies on the LOV fragments LOV1, LOV2, LOV2-linker, and LOV2-kinase, and full-length phot2, using small-angle X-ray scattering (SAXS). The aim of the study was to understand structural changes under BL irradiation and discuss the molecular mechanism that enhance the phosphorylation activity under BL. SAXS is a suitable technique for visualizing molecular structures of proteins in solution at low resolution and is advantageous for monitoring their structural changes in the presence of external physical and/or chemical stimuli. Structural parameters and molecular models of the recombinant specimens were obtained from SAXS profiles in the dark, under BL irradiation, and after dark reversion. LOV1, LOV2, and LOV2-linker fragments displayed minimal structural changes. However, BL-induced rearrangements of functional domains were noted for LOV2-kinase and full-length phot2. Based on the molecular model together with the absorption measurements and biochemical assays, we discuss the intramolecular interactions and domain motions necessary for BL-enhanced phosphorylation activity of phot2.
KW - Photoreceptor protein
KW - Phototropin2
KW - Signal transduction
KW - Small-angle X-ray scattering
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U2 - 10.3390/ijms21186638
DO - 10.3390/ijms21186638
M3 - Article
C2 - 32927860
AN - SCOPUS:85090621945
SN - 1661-6596
VL - 21
SP - 1
EP - 21
JO - International journal of molecular sciences
JF - International journal of molecular sciences
IS - 18
M1 - 6638
ER -