GUN4, a Regulator of Chlorophyll Synthesis and Intracellular Signaling

作者：Robert M. Larkin, José M. Alonso, Joseph R. Ecker, Joanne Chory · 发表于：Science · 年份：2003 · DOI：10.1126/science.1079978 · 被引用次数：526 · 研究领域：Photosynthetic Processes and Mechanisms、Algal biology and biofuel production、Plant responses to water stress

Nuclear genes control plastid differentiation in response to developmental signals, environmental signals, and retrograde signals from plastids themselves. In return, plastids emit signals that are essential for proper expression of many nuclear photosynthetic genes. Accumulation of magnesium-protoporphyrin IX (Mg-Proto), an intermediate in chlorophyll biosynthesis, is a plastid signal that represses nuclear transcription through a signaling pathway that, in Arabidopsis, requires the GUN4 gene. GUN4 binds the product and substrate of Mg- chelatase, an enzyme that produces Mg-Proto, and activates Mg-chelatase. Thus, GUN4 participates in plastid-to-nucleus signaling by regulating Mg-Proto synthesis or trafficking.