Regulates G protein-coupled receptor signaling cascades, including signaling downstream of the N-formylpeptide chemoattractant receptors and leukotriene receptors (PubMed:10480894). Inhibits B cell chemotaxis toward CXCL12 (By similarity). Inhibits signal transduction by increasing the GTPase activity of G protein alpha subunits thereby driving them into their inactive GDP-bound form (PubMed:10480894, PubMed:18434541). {ECO:0000250|UniProtKB:Q9JL25, ECO:0000269|PubMed:10480894, ECO:0000269|PubMed:18434541}. This is the function of Ensembl gene identifier ENSG00000090104 (RGS1, regulator of G protein signaling 1).