Cryptochrome 1 promotes photomorphogenesis in Arabidopsis by displacing substrates from the COP1 ubiquitin ligase.

ABSTRACT: In blue light, cryptochrome photoreceptors inhibit the key repressor of light signaling, the COP1/SPA ubiquitin ligase, to promote photomorphogenic responses. This inhibition relies on the direct interaction between COP1 and cryptochromes. Here, we analyzed the molecular mechanism of CRY1-mediated inhibition of COP1. We show that the VP motif in the C-terminal domain of CRY1 is essential for the COP1-CRY1 interaction in Arabidopsis. Phenotypic analysis of transgenic Arabidopsis plants harboring a mutation in the VP motif reveals that the VP motif of CRY1 is required for blue light-induced responses, such as seedling de-etiolation and anthocyanin biosynthesis. Via its VP motif, CRY1 inhibits the interaction between COP1 and the COP1 substrate transcription factors PAP2 and HY5. Replacing th

SUBMITTER: Trimborn L 

PROVIDER: S-EPMC11886768 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature