Together with flp-18, plays a homeostatic role by acting on the GABAergic neural transmission at neuromuscular junctions to prevent overexcitation of the locomotor circuit. Inhibits the activity of dissected pharyngeal myogenic muscle system. DPNFLRF-amide: Inhibits the activity of dissected pharyngeal myogenic muscle system. Acts as a ligand for the npr-22 receptor in vitro. Each flp gene is expressed in a distinct set of neurons. Flp-1 is expressed in the AVA interneurons, the M5 cholinergic pharyngeal motoneurons, and the AIA, AIY, AVE, AVK, RIG and RMG neurons. May be processed by convertase egl-3. Expressed at about a twofold higher level than isoform Long. Belongs to the FARP (FMRFamide related peptide) family.