Figure 5. Expression of flp-19::GFP in the BAG Neurons is Controlled by Parallel Pathways.

Schematic representation of the proposed model of regulation of flp-19::GFP expression in BAG neurons. The GCY-9 receptor binds CO₂ converting GTP into cGMP. cGMP triggers opening of the cyclic nucleotide-gated TAX-2/TAX-4 cation channels, allowing Ca²⁺ to enter the neuron, leading to regulation of an unknown transcription factor (TF A) that positively regulates the expression of flp-19::GFP. PDE-1 reduces the levels of cGMP, opposing the action of GCY-9. In parallel, CRH-1 regulates the expression of flp-19::GFP by a signaling pathway involving the cAMP-dependent protein kinase KIN-2.