Enables S-adenosylmethionine-dependent methyltransferase activity. Involved in positive regulation of cold-induced thermogenesis. Acts upstream of or within blastocyst hatching and sphingomyelin biosynthetic process. Located in endoplasmic reticulum membrane. Is expressed in several structures, including central nervous system; early conceptus; liver; lung; and secondary oocyte. Orthologous to human PEMT (phosphatidylethanolamine N-methyltransferase). [provided by Alliance of Genome Resources, Apr 2022]