Submitted to: Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/1999
Publication Date: N/A
Citation: Quail, P.H., Hoecker, U., Tepperman, J.M. 1999. Spa1, a wd-repeat protein specific to phytochrome a signal transduction. Science 284(5413):496-499. Interpretive Summary: A component in the phytochrome A signaling pathway, SPA1 (for "suppressor of phyA-105"), functions in repression of photomorphogenesis and is required for normal photosensory specificity of phytochrome A.
Technical Abstract: The five members of the phytochrome photoreceptor family of Arabidopsis thaliana control morphogenesis differentially in response to light. Genetic analysis has identified a signaling pathway that is specifically activated by phytochrome A. A component in this pathway, SPA1 (for "suppressor of phyA-105"), functions in repression of photomorphogenesis and is required for normal photosensory specificity of phytochrome A. Molecular cloning of the SPA1 gene indicates that SPA1 is a WD (tryptophan-aspartic acid)-repeat protein that also shares sequence similarity with protein kinases. SPA1 can localize to the nucleus, suggesting a possible function in phytochrome A-specific regulation of gene expression.