TY - JOUR
T1 - Characterization of the APRR9 Pseudo-Response Regulator Belonging to the APRR1/TOC1 Quintet in Arabidopsis thaliana
AU - Ito, Shogo
AU - Matsushika, Akinori
AU - Yamada, Hisami
AU - Sato, Shusei
AU - Kato, Tomohiko
AU - Tabata, Satoshi
AU - Yamashino, Takafumi
AU - Mizuno, Takeshi
N1 - Funding Information:
This study was supported by Grants-in-Aid from the Ministry of Education, Science, Sports, and Culture of Japan, and also the Ministry of Agriculture, Forestry and Fisheries of Japan. Many thanks are due to the followings: a set of phy mutants (Dr. G.C. Whitelam, University of Leicester, U.K.), a set of cry mutants (Dr. C. Lin, University of Cali- fornia, U.S.A.), a set of phot mutants (Drs. T. Kagawa and M. Wada, National Institute for Basic Biology, Japan). Thanks are also due to The Salk Institute Genomic Analysis Laboratory (California, U.S.A.)
PY - 2003/11
Y1 - 2003/11
N2 - In Arabidopsis thaliana, a number of circadian-associated factors have been identified, including TOC1 (TIMING OF CAB EXPRESSION1) that is believed to be a component of the central oscillator. TOC1 is a member of a small family of proteins, designated as ARABIDOPSIS PSEUDO-RESPONSE REGULATORS (APRR1/TOC1, APRR3, APRR5, APRR7, and APRR9). As demonstrated previously, these APRR1/TOC1 quintet members are crucial for a better understanding of the molecular links between circadian rhythms and photosensory signal transduction. Here we focused on the light-induced quintet member, APRR9, and three critical issues with regard to this member were simultaneously addressed: (i) clarification of the mechanism underlying the light-dependent acute response of APRR9, (ii) clarification of the phenotype of a null mutant of APRR9, (iii) identification of protein(s) that interacts with APRR9. In this study, we present the results that support the following views. (i) A phytochrome-mediated signaling pathway(s) activates the transcription of APRR9, leading to the acute light response of APRR9. (ii) The severe mutational lesion of APRR9 singly, if not directly, affects the period (and/or phase) of free-running rhythms, in continuous light, of every circadian-controlled gene tested, including the clock genes, APRR1/TOC1, CCA1, and LHY. (iii) The APRR9 protein is capable of interacting with APRR1/TOC1, suggesting a hetrodimer formation between these cognate family members. These results are discussed within the context of a current consistent model of the Arabidopsis circadian oscillator.
AB - In Arabidopsis thaliana, a number of circadian-associated factors have been identified, including TOC1 (TIMING OF CAB EXPRESSION1) that is believed to be a component of the central oscillator. TOC1 is a member of a small family of proteins, designated as ARABIDOPSIS PSEUDO-RESPONSE REGULATORS (APRR1/TOC1, APRR3, APRR5, APRR7, and APRR9). As demonstrated previously, these APRR1/TOC1 quintet members are crucial for a better understanding of the molecular links between circadian rhythms and photosensory signal transduction. Here we focused on the light-induced quintet member, APRR9, and three critical issues with regard to this member were simultaneously addressed: (i) clarification of the mechanism underlying the light-dependent acute response of APRR9, (ii) clarification of the phenotype of a null mutant of APRR9, (iii) identification of protein(s) that interacts with APRR9. In this study, we present the results that support the following views. (i) A phytochrome-mediated signaling pathway(s) activates the transcription of APRR9, leading to the acute light response of APRR9. (ii) The severe mutational lesion of APRR9 singly, if not directly, affects the period (and/or phase) of free-running rhythms, in continuous light, of every circadian-controlled gene tested, including the clock genes, APRR1/TOC1, CCA1, and LHY. (iii) The APRR9 protein is capable of interacting with APRR1/TOC1, suggesting a hetrodimer formation between these cognate family members. These results are discussed within the context of a current consistent model of the Arabidopsis circadian oscillator.
KW - APRR1/TOC1 quintet
KW - Arabidopsis thaliana
KW - Circadian rhythm
KW - Light signaling
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U2 - 10.1093/pcp/pcg136
DO - 10.1093/pcp/pcg136
M3 - Article
C2 - 14634162
AN - SCOPUS:0346146962
VL - 44
SP - 1237
EP - 1245
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
SN - 0032-0781
IS - 11
ER -