The APRR1/TOC1 Quintet Implicated in Circadian Rhythms of Arabidopsis thaliana: I. Characterization with APRR1-Overexpressing Plants Export

@article{citeulike:3072456, abstract = {Several Arabidopsis genes have been proposed to encode potential clock-associated components, including the Myb-related CCA1 and LHY transcription factors and a member of the novel family of pseudo response regulators (APRR1/TOC1). We previously showed that mRNAs of the APRR1/TOC1 family of genes start accumulating after dawn rhythmically and sequentially at approximately 2 h intervals in the order: APRR9[-\>]APRR7[-\>]APRR5[-\>]APRR3[-\>] APRR1/TOC1. Here we constructed APRR1-overexpressing (APRR1-ox) plants, and examined certain circadian profiles for APRRs, CCA1, LHY, GI, CCR2, and CAB2. The free-running circadian rhythms of the APRR1/TOC1 family of genes, including APRR1, were dampened in APRR1-ox plants. In particular, the light-inducible expression of APRR9 was severely repressed in APRR1-ox plants, suggesting that there is a negative APRR1[-\>]APRR9 regulation. The free-running robust rhythm of CAB2 was also dampened in APRR1-ox. The circadian profiles of potential clock-associated genes, CCA1, LHY, GI, and CCR2 were all markedly altered in APRR1-ox, each in characteristic fashion. To gain further insight into the molecular function of APRR1, we then identified a novel Myc-related bHLH transcription factor, which physically associated with APRR1. This protein (named PIL1) is similar in its amino acid sequence to PIF3, which has been identified as a phytochrome-interacting transcription factor. These results are discussed in relation to the current idea that APRR1 (TOC1) plays a role within, or close to, the Arabidopsis central oscillator. 10.1093/pcp/pcf005}, author = {Makino, Seiya and Matsushika, Akinori and Kojima, Masaya and Yamashino, Takafumi and Mizuno, Takeshi}, citeulike-article-id = {3072456}, citeulike-linkout-0 = {http://dx.doi.org/10.1093/pcp/pcf005}, citeulike-linkout-1 = {http://pcp.oxfordjournals.org/cgi/content/abstract/43/1/58}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/11828023}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=11828023}, day = {1}, doi = {10.1093/pcp/pcf005}, journal = {Plant Cell Physiol.}, keywords = {arabidopsis, cab2, ccr2, lhy, toc1}, month = {January}, number = {1}, pages = {58--69}, posted-at = {2008-08-01 15:37:04}, priority = {4}, title = {The APRR1/TOC1 Quintet Implicated in Circadian Rhythms of Arabidopsis thaliana: I. Characterization with APRR1-Overexpressing Plants}, url = {http://dx.doi.org/10.1093/pcp/pcf005}, volume = {43}, year = {2002} }

TY - JOUR ID - citeulike:3072456 L3 - citeulike-article-id:3072456 N2 - Several Arabidopsis genes have been proposed to encode potential clock-associated components, including the Myb-related CCA1 and LHY transcription factors and a member of the novel family of pseudo response regulators (APRR1/TOC1). We previously showed that mRNAs of the APRR1/TOC1 family of genes start accumulating after dawn rhythmically and sequentially at approximately 2 h intervals in the order: APRR9[->]APRR7[->]APRR5[->]APRR3[->] APRR1/TOC1. Here we constructed APRR1-overexpressing (APRR1-ox) plants, and examined certain circadian profiles for APRRs, CCA1, LHY, GI, CCR2, and CAB2. The free-running circadian rhythms of the APRR1/TOC1 family of genes, including APRR1, were dampened in APRR1-ox plants. In particular, the light-inducible expression of APRR9 was severely repressed in APRR1-ox plants, suggesting that there is a negative APRR1[->]APRR9 regulation. The free-running robust rhythm of CAB2 was also dampened in APRR1-ox. The circadian profiles of potential clock-associated genes, CCA1, LHY, GI, and CCR2 were all markedly altered in APRR1-ox, each in characteristic fashion. To gain further insight into the molecular function of APRR1, we then identified a novel Myc-related bHLH transcription factor, which physically associated with APRR1. This protein (named PIL1) is similar in its amino acid sequence to PIF3, which has been identified as a phytochrome-interacting transcription factor. These results are discussed in relation to the current idea that APRR1 (TOC1) plays a role within, or close to, the Arabidopsis central oscillator. 10.1093/pcp/pcf005 IS - 1 JF - Plant Cell Physiol. EP - 69 TI - The APRR1/TOC1 Quintet Implicated in Circadian Rhythms of Arabidopsis thaliana: I. Characterization with APRR1-Overexpressing Plants VL - 43 SP - 58 KW - arabidopsis KW - cab2 KW - ccr2 KW - lhy KW - toc1 AU - Makino, Seiya AU - Matsushika, Akinori AU - Kojima, Masaya AU - Yamashino, Takafumi AU - Mizuno, Takeshi PY - 2002/01/01/ UR - http://dx.doi.org/10.1093/pcp/pcf005 ER -