Fig. 7: A hypothetical model for blue-light regulation of thermosensory flowering via the CRY2–CIS1–FLM signaling pathway.
From: CRY2 interacts with CIS1 to regulate thermosensory flowering via FLM alternative splicing
At low ambient temperatures without blue light, CRY2 is inactive, CIS1 protein is unstable, the 3ʹ splice site of the second FLM intron is a weak AS site because of the G tract sequence, leading to more accumulation of FLM β. When there is blue light, CIS1 protein is stabilized; photoexcited CRY2 forms homodimers and interacts with CIS1 to promote its binding to intron 2 or exon 3 in the FLM pre-RNA. CIS1 also interacts with SF1 and U2AF65A to recruit U2-snRNP to promote the accumulation of non-FLM β including FLM δ and other FLM variants (oFLM).
