pGC

pGC is an abbreviation most commonly used to refer to plant guanylate cyclases, a group of enzymes in plants that catalyze the conversion of guanosine triphosphate (GTP) into cyclic guanosine monophosphate (cGMP). In plant cells, cGMP acts as a second messenger that participates in signaling pathways triggered by light, hormones, and environmental cues. Plant guanylate cyclases can occur as standalone cytosolic enzymes or as catalytic domains within larger sensor or receptor-like proteins, including receptor-like kinases that harbor GC activity in their cytoplasmic regions. The GC catalytic domain produces cGMP, which then interacts with downstream components such as cGMP-binding proteins and cyclic nucleotide-gated channels to influence cellular responses.

Structural and functional aspects of pGCs include diversity in localization and organization. Some pGCs are soluble enzymes, while others are embedded in membranes as part of receptor-like proteins. The GC catalytic domain typically adopts a compact fold responsible for converting GTP to cGMP, enabling rapid signal generation in response to stimuli. The produced cGMP can modulate ion fluxes, enzyme activities, and other signaling pathways, contributing to coordinated physiological responses.

Physiological roles attributed to pGC signaling in plants encompass stomatal movement, pollen tube growth, root development, gravitropism, and responses to abiotic and biotic stresses. Genetic, biochemical, and pharmacological studies show that altering cGMP levels or pGC activity affects these processes, indicating that pGCs participate in integrating environmental information with cellular behavior.

Distribution and regulation of pGCs have been observed across land plants and some algae. Genomes of model species such as Arabidopsis and rice encode putative pGCs, and their activity can be modulated by factors such as calcium, nitric oxide, and phosphorylation. cGMP signaling often intersects with calcium signaling and other second-m messenger networks to shape plant physiology.