Oct 16, 2020 · HY5 acts as a master regulator and binds to promoters of close to 4000 genes, thereby, regulating wide diversity of photomorphogenic responses. It physically interacts with CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a negative regulator of photomorphogenesis.

The hyperphotomorphogenic phenotype caused by the over-expression of a mutant HY5, which lacks the COP1-interactive domain, supports the regulatory role of HY5-COP1 interaction. Further, HY5 is capable of directly interacting with the CHS1 minimal promoter and is essential for its light activation.

Jan 29, 2025 · Unphosphorylated CRY1 exhibits decreased activity in suppressing the interaction of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) with ELONGATED HYPOCOTYL 5 (HY5), leading to excessive degradation of HY5 under heat stress in blue light.

Oct 30, 2019 · In this review, I predominantly summarize recent advances on CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), ELONGATED HYPOCOTYL 5 (HY5), and B-BOX CONTAINING PROTEINs (BBXs)-mediated light signal transduction pathways.

Constitutive photomorphogenic1 (COP1)-Suppressor of phytochrome A-105 (SPA) E3 ubiquitin ligase complex promotes ubiquitination and degradation of HY5 to repress photomorphogenesis in darkness. HY5 is also regulated by phosphorylation at serine 36 residue.

May 25, 2000 · Light may inactivate COP1, reducing its nuclear abundance and allowing the accumulation of HY5. Therefore, COP1 may directly target HY5 for proteasome-mediated degradation.

Arabidopsis COP1 acts as a light-inactivable repressor of photomorphogenic development, but its molecular mode of action remains unclear. Here, we show that COP1 negatively regulates HY5, a bZIP protein and a positive regulator of photomorphogenic development.

The activity of HY5 is largely controlled by COP1, a repressor of photomorphogenesis whose activity is abrogated by light. HY5 and COP1 interact both genetically and physically (Ang and Deng, 1994; Ang et al., 1998), and this interaction negatively regulates HY5 activity.

Oct 16, 2020 · HY5 acts as a master regulator and binds to promoters of close to 4000 genes, thereby, regulating wide diversity of photomorphogenic responses. It physically interacts with CONSTITUTIVE...

Jan 1, 1998 · Here, we show that COP1 negatively regulates HY5, a bZIP protein and a positive regulator of photomorphogenic development. Both in vitro and in vivo assays indicate that COP1 interacts directly and specifically with HY5.