Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. In the 1-cell embryo, probably together with gpa-16, controls nuclear rotation and spindle elongation during mitosis (PubMed:14534135). During the first embryonic cell divisions, plays a role in gpr-1/2 cortical localization and in the proper orientation of EMS blastomere mitotic spindle (PubMed:14534135). Polarity determinants (par genes) may regulate lin-5/gpr-1/gpr-2/goa-1 locally to create the asymmetric forces that drive spindle movement (PubMed:12730122). Involved in chemosensory responses to attractive and repellent odors detected by AWC and AWB sensory neurons, respectively (PubMed:23954825). In ASER neurons, acts downstream of glr-3 to regulate cold avoidance behavior via calcium signaling, and it may also play a role in sensing cold in the intestine (PubMed:31474366). Negatively regulates axon regeneration after injury downstream of the inhibitory compound arachidonoyl ethanolamide (AEA) by antagonizing the activation of the JNK pathway (mlk-1/mek-1/kgb-1) (PubMed:23072806). In neurons, may negatively regulate diacylglycerol (DAG) production mediated by egl-30 signaling cascade and thereby negatively regulates acetylcholine release (PubMed:22897658). Couples to the muscarinic acetylcholine receptor gar-2 to negatively regulate cholinergic receptor activity in the presence of high levels of acetylcholine in ventral cord motor neurons (PubMed:18614679). Plays a role in the navigational capacity of sperm and the targeting of sperm derived from males to the fertilization site in the uterus of hermaphrodites (PubMed:28662030). Involved in egg-laying and in regulating dopamine-mediated locomotion (PubMed:8548815, PubMed:15378064). Most likely couples to the dopamine receptors dop-2 and dop-3 to positively regulate the dopamine-mediated suppression of crh-1/CREB1 transcription factor activation in cholinergic SIA neurons in the presence of food (PubMed:19609300). G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site (By similarity). Interacts (in GDP-bound form) with gpr-1; gpr-1 forms a complex with gpr-2 and lin-5 (PubMed:12730122). Interacts (in GDP-bound form) with gpb-1 (PubMed:12730122). Interacts (in GDP-bound form) with gbas-1 (via GBA motif); the interaction leads to activation of goa-1 (PubMed:26659249). Expressed in the ASER neuron and the intestine. Prolonged exposure to attractive odorant benzaldehyde results in a loss of adaptive response characterized by a decrease in odor seeking behavior and in a loss of egl-4 nuclear translocation. Loss of chemotaxis response to the repellent odor 2-nonanone (PubMed:23954825). Increased egg laying; eggs are prematurely laid at one-cell to 8-cell stage (PubMed:8548815). Increased locomotion (PubMed:8548815). Increases diacylglycerol (DAG) levels along axons. Increases paralysis following treatment with acetylcholinesterase inhibitor aldicarb which is partially reduced in a drn-1 mutant background (PubMed:22897658). In a mutant background which expresses gar-2 in all cholinergic motor neurons, eliminates the resistance to Aldicarb that is characteristic of the gar-2 single mutant (PubMed:18614679). Simultaneous RNAi-mediated knockdown of both goa-1 and gpa-16 causes, in the one-cell embryo, a lack of nuclear rocking movements from prophase to metaphase and symmetric spindle elongation without transversal oscillations of the poles during anaphase (PubMed:14534135). At the 2-cell stage embryo, nuclei are mispositioned and fail to exhibit nuclear rotation (PubMed:14534135). In addition, causes a loss of gpr-1/2 cortical localization in 2-cell and 4-cell stage embryos (PubMed:14534135). Belongs to the G-alpha family. G(i/o/t/z) subfamily.