Enables guanyl-nucleotide exchange factor activity. Involved in collagen and cuticulin-based cuticle development; epidermis development; and molting cycle. Located in collagen and cuticulin-based cuticle extracellular matrix. Expressed in several structures, including cholinergic neurons; hermaphrodite somatic gonadal cell;
hyp4; nerve ring neurons; and ventral nerve cord. Human ortholog(s) of this gene implicated in familial adult myoclonic epilepsy 7. Is an ortholog of human RAPGEF2 (Rap guanine nucleotide exchange factor 2) and RAPGEF6 (Rap guanine nucleotide exchange factor 6).