CONSTANS and the CCAAT Box Binding Complex Share a Functionally Important Domain and Interact to Regulate Flowering of Arabidopsis[W][OA]

By Stephan Wenkel, F. Turck, Kamy Singer, L. Gissot, José Le gourrierec, A. Samach, G. Coupland. The Plant Cell Online, 2006

623 citations recorded by the source corpus.

The CCT (for CONSTANS, CONSTANS-LIKE, TOC1) domain is found in 45 Arabidopsis thaliana proteins involved in processes such as photoperiodic flowering, light signaling, and regulation of circadian rhythms. We show that this domain exhibits similarities to yeast HEME ACTIVATOR PROTEIN2 (HAP2), which is a subunit of the HAP2/HAP3/HAP5 trimeric complex that binds to CCAAT boxes in eukaryotic promoters. Moreover, we demonstrate that CONSTANS (CO), which promotes Arabidopsis flowering, interacts with At HAP3 and At HAP5 in yeast, in vitro, and in planta. Mutations in CO that delay flowering affect residues highly conserved between CCT and the DNA binding domain of HAP2. Taken together, these data suggest that CO might replace At HAP2 in the HAP complex to form a trimeric CO/At HAP3/At HAP5 complex. Flowering was delayed by overexpression of At HAP2 or At HAP3 throughout the plant or in phloem companion cells, where CO is expressed. This phenotype was correlated with reduced abundance of FLOWERING LOCUS T (FT) mRNA and no change in CO mRNA levels. At HAP2 or At HAP3 overexpression may therefore impair formation of a CO/At HAP3/At HAP5 complex leading to reduced expression of FT. During plant evolution, the number of genes encoding HAP proteins was greatly amplified, and these proteins may have acquired novel functions, such as mediating the effect of CCT domain proteins on gene expression.

Subfields: Molecular Biology, Plant Science

View Paper: https://www.semanticscholar.org/paper/062198029118066adcc98aad075cc62c256d0e90

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Molecular Biology

1. F. Fornara
2. F. Turck
3. G. Coupland
4. Jian‐Kang Zhu
5. David L. Wild
6. David A. Rand
7. Youn-sung Kim
8. R. Amasino

In Plant Science

1. Qifa Zhang
2. F. Fornara
3. Xin‐Jian He
4. F. Turck
5. Yongzhong Xing
6. Youko Oono
7. Hailing Jin
8. Wenxue Li

Citations in the corpus

• Regulation and identity of florigen: FLOWERING LOCUS T moves center stage. (2008, background): “This hypothesis is based on the finding that the CCT domain of CO and several Arabidopsis or tomato COLs interact with subunits of the eukaryotic CCAAT-box binding complex (7, 94) and that the CCT domain shows structure and sequence homology to the sequencespecific DNA binding domain of HAP2 (94).”
• High-Resolution Temporal Profiling of Transcripts during Arabidopsis Leaf Senescence Reveals a Distinct Chronology of Processes and Regulation[C][W][OA] (2011, background): “…binding factor family were also significantly upregulated; factors in this family form the heterotrimeric NF-Y binding complex (consisting of NF-YA, NF-YB, and NF-YC subunits) that has been shown to influence flowering time and stress responses in plants (Wenkel et al., 2006; Liu and Howell, 2010).”
• The Arabidopsis NFYA5 Transcription Factor Is Regulated Transcriptionally and Posttranscriptionally to Promote Drought Resistance[W] (2008, background): “…of the proteins vary, the NF-YAs contain a highly conserved core region that consists of two functional subdomains: an NF-YB/NF-YC binding subdomain and a DNA binding subdomain, which are connected by a small linker (Romier et al., 2003; Wenkel et al., 2006; see Supplemental Figure 1 online).”
• Natural variation in Ghd7 is an important regulator of heading date and yield potential in rice (2008, methodology): “, and that this domain is similar to yeast HEME ACTIVATOR PROTEIN2 (HAP2), a subunit of the HAP2-HAP3-HAP5 trimeric complex with DNA binding activit”