[Tu, Shih-Long] New mechanism for regulating gene expression by photoreceptors

The red/far-red light photoreceptor phytochrome plays vital roles in plant growth and development. It senses and optimizes the gene expression at different level in response to the changing environment. In addition to transcription, which directly regulate gene expression, accumulating evidence has showed that alternative splicing is also regulated by phytochromes. However, detailed mechanism is still not clear. Dr. Tu and his research group discovered that in moss Physcomitrella patens, phytochromes interact with a splicing regulator PphnRNP-F1 in a red light dependent manner. The interaction increases the protein level of PphnRNP-F1. Moreover, PphnRNP-F1 could be further recruited to the pre-mRNA by a GAA-repetitive, cis-regulatory element located on the exonic region to modulate alternative splicing. Their finding provides evidence to demonstrate a novel phytochrome-mediated signaling pathway for regulation of pre-mRNA splicing.