Enables IMP dehydrogenase activity. Involved in 'de novo' XMP biosynthetic process and GMP biosynthetic process. Acts upstream of or within cellular response to interleukin-4; lymphocyte proliferation; and purine nucleotide biosynthetic process. Predicted to be located in cytosol and nucleus. Predicted to be active in cytoplasm. Is expressed in several structures, including alimentary system; brain; heart; respiratory system; and sensory organ. Orthologous to human IMPDH2 (inosine monophosphate dehydrogenase 2). [provided by Alliance of Genome Resources, Apr 2022]