High impact information on FHY3

• In addition, FHY1 transcript levels are regulated by light, and by the product of FHY3, another gene implicated in FR signaling [1].
• Our data indicate that FHY3, together with FAR1, defines a key module in a signaling network underlying phyA-mediated FR light responses [2].
• The fhy3 (for far-red elongated hypocotyl3) mutant of Arabidopsis thaliana is involved in independently gating signaling from a group of photoreceptors to an individual response. fhy3 shows an enhanced response to red light during seedling deetiolation [3].
• However, unlike previously described Arabidopsis gating mutants that gate all light signaling, gating of direct red light-induced gene expression in fhy3 is unaffected [3].
• Furthermore, the response to far-red light depended on functional FHY1 but not on FIN219 and FHY3 [4].

Biological context of FHY3

• Taken together, our data suggest that FAR1 and FHY3 may function 'permissively' outside the signal transduction pathway of light-regulated development, yet be required for the expression of transcriptional regulatory components [5].
• The FHY3 and FAR1 genes encode transposase-related proteins involved in regulation of gene expression by the phytochrome A-signaling pathway [5].
• Further, this study also provides genomics evidence for the partial functional redundancy between FAR1 and FHY3 [6].
• There are 12 additional FHY3/FAR1-related genes in the Arabidopsis genome [7].
• Moreover, overexpression of partial fragments of FHY3 can cause a dominant-negative interference phenotype on phyA signaling that is stronger than those of the fhy3 or far1 null mutants [2].

Anatomical context of FHY3

• FHY1, FAR1 and FHY3 most likely act upstream in the phyA signaling network, close to the phyA photoreceptor itself [6].

Other interactions of FHY3

• The fhy1 and fhy3 mutants show the most significant differences in light regulation between the two genes, with both showing a strong inhibition of HEMA1 expression under continuous red light [8].

References