Disease relevance of CRY2

• That is, CRY1 and CRY2 genes may originate from an endosymbiotic ancestor of modern-day alpha-proteobacteria, while the CRY3 gene may originate from an endosymbiotic ancestor of modern-day cyanobacteria [1].
• The absence of significant effects on resistance suggests either that any putative AT-PHH1 DNA repair activity requires cofactors/chromophores not present in yeast or E. coli, or that AT-PHH1 encodes a blue-light/ultraviolet-A receptor rather than a DNA repair protein [2].

High impact information on CRY2

• In contrast, the exaggerated temperature response of cryptochrome-2 mutants is caused by temperature-dependent redundancy with the phytochrome A photoreceptor [3].
• We show that the unique EDI flowering phenotype results from a single amino-acid substitution that reduces the light-induced downregulation of CRY2 in plants grown under short photoperiods, leading to early flowering [4].
• Our results suggest that, in the absence of light, cry2 remains unphosphorylated, inactive and stable; absorption of blue light induces the phosphorylation of cry2, triggering photomorphogenic responses and eventually degradation of the photoreceptor [5].
• Here we report that cry2 undergoes a blue-light-dependent phosphorylation, and that cry2 phosphorylation is associated with its function and regulation [5].
• Functional interaction of phytochrome B and cryptochrome 2 [6].

Biological context of CRY2

• Blue light regulates plant growth and development, and three photoreceptors, CRY1, CRY2, and NPH1, have been identified [7].
• Expression of the tomato (Solanum lycopersicum) CRY2 gene was altered through a combination of transgenic overexpression and virus-induced gene silencing [8].
• In the present report, we have used a set of Arabidopsis L er transgenic plants carrying four different functional CRY2 transgenes for phenotypic analyses, with the aim of exploring the extent of pleiotropy of CRY2 allelic variation [9].
• Analysis of fifteen AT-PHH1 genomic isolates reveals a single gene, with three introns in the coding sequence and one in the 5'-untranslated leader [2].
• Whereas the B haplogroup cannot be delimited to <16 kb around CRY2, the AS haplogroup is characterized almost exclusively by the nucleotide polymorphisms directly associated with the serine replacement in CRY2; this finding strongly suggests that the serine substitution is directly responsible for the AS early flowering phenotype [10].

Anatomical context of CRY2

• Here we report that mutant plants lacking both the CRY1 and the CRY2 blue-light photoreceptors are deficient in the phototropic response [11].
• Fusion proteins consisting of the green fluorescent protein (GFP) and different fragments of CRY2 were expressed in parsley protoplasts and the localization of the fusion proteins was determined by fluorescence and confocal laser scanning microscopy [12].

Associations of CRY2 with chemical compounds

• Additional cryptochrome-dependent responses, such as blue-light-dependent anthocyanin accumulation and blue-light-dependent degradation of CRY2 protein, were also enhanced at the higher magnetic intensity [13].
• CRY2 DNA sequences reveal strong LD and the existence of two highly differentiated haplogroups (A and B) across the gene; in addition, a haplotype possessing a radical glutamine-to-serine replacement (AS) occurs within the more common haplogroup [10].
• LOV (light, oxygen, or voltage) domains of the blue-light photoreceptor phototropin (nph1): binding sites for the chromophore flavin mononucleotide [14].
• The lack of a specific blue light response in the zeaxanthinless npq1 mutant provides genetic evidence for the role of zeaxanthin as a blue light photoreceptor in guard cells [15].

Other interactions of CRY2

• Mutations in either the PHYB gene or both the CRY1 and CRY2 genes resulted in the loss of the light-quality-sensitive phase manifested during floral development [16].
• Cryptochrome 1, cryptochrome 2, and phytochrome a co-activate the chloroplast psbD blue light-responsive promoter [17].
• Unexpected roles for cryptochrome 2 and phototropin revealed by high-resolution analysis of blue light-mediated hypocotyl growth inhibition [18].
• The analysis of mutants of the photoperiod pathway showed epistasis of co and gi to the CRY2 alleles, indicating that cry2 needs the product of CO and GI genes to promote flowering [19].

Analytical, diagnostic and therapeutic context of CRY2

• Photoreceptor concentration as determined by western-blot analysis showed a greater stability of CRY2 protein under the monochromatic light conditions used in this study as compared with broad band blue light, suggesting a complex mechanism of photoreceptor activation [20].
• RT-PCR results show that CRY2 has been transcribed in root, leaf and mesocotyl in sorghum seedlings [21].
• The results of sequence analysis shows that it contains a complete open reading frame encoding a predicted protein of 690 amino acids sharing 87% identity with the CRY2 of rice, but only 45.5% with that of Arabidopsis and 57% with that of tomato [21].
• PhyB interacts directly with cry2 as observed in co-immunoprecipitation experiments with transgenic Arabidopsis plants overexpressing cry2 [6].
• Phototropin (phot) is a blue-light photoreceptor for phototropic responses, relocation of chloroplasts, and stomata opening in plants [22].

References