Enables activin binding activity; growth factor binding activity; and protein kinase activity. Involved in blood vessel remodeling; negative regulation of cold-induced thermogenesis; and vasculature development. Acts upstream of or within several processes, including animal organ development; embryonic morphogenesis; and insulin secretion. Predicted to be located in cytoplasm. Predicted to be part of activin receptor complex. Predicted to be active in plasma membrane. Is expressed in several structures, including alimentary system; egg cylinder; genitourinary system; nervous system; and sensory organ. Used to study right atrial isomerism and visceral heterotaxy. Human ortholog(s) of this gene implicated in visceral heterotaxy. Orthologous to human ACVR2B (activin A receptor type 2B). [provided by Alliance of Genome Resources, Apr 2022]