High impact information on COL1

• 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 [1].
• Systemic pathogen-induced expression of the plant defensin gene was unaffected in Arabidopsis transformants (nahG) or mutants (npr1 and cpr1) affected in the salicylic acid response but was strongly reduced in the Arabidopsis mutants eln2 and col1 that are blocked in their response to ethylene and methyl jasmonate, respectively [2].
• Summary CONSTANS-Like (COL) proteins are plant-specific nuclear regulators of gene expression but do not contain a known DNA-binding motif [3].
• Overexpression of COL9, a CONSTANS-LIKE gene, delays flowering by reducing expression of CO and FT in Arabidopsis thaliana [4].
• They were highly similar to each other and to Hd1, and in addition harbored two conserved regions: two zinc finger motifs and CONSTANS, CONSTANS-LIKE and TIMING OF CAB EXPRESSION 1 (CCT) domain like CO/Hd1 [5].

Biological context of COL1

• However, analysis of circadian phenotypes in the transgenic plants showed that over-expression of COL1 can shorten the period of two distinct circadian rhythms [6].
• In contrast, the nucleotide sequence of the B. nigra COL1 (Bni COL1) gene located 3.5 kb upstream of Bni COa was highly diverged between the alleles from early and late plants [7].
• The Arabidopsis CONSTANS (CO) gene is a key regulator of the long day (LD)-dependent flowering pathway and two CO homologous genes COL1 and COL2 are involved in the regulation of the circadian rhythm [8].
• The deduced amino acid sequence of PnCOL1 was 34% identical to that of PnCO, but 32%, 34%, and 34% identical to those of CO, COL1, and COL2, respectively [8].
• Expressed sequence tags of radish flower buds and characterization of a CONSTANS LIKE 1 gene [9].

Physical interactions of COL1

• The LKP2-binding site in CO or COL1 was near the center of each protein [10].

Other interactions of COL1

• We analyzed transgenic plants misexpressing COL1, COL2 and CO [6].
• However, co-expression of CFP-LKP2 with YFP fused to either CO or COL1 resulted in the recruitment of CFP-LKP2 in nuclear bodies [10].

References