Enables phosphoenolpyruvate carboxykinase (GTP) activity. Involved in oxaloacetate metabolic process and positive regulation of memory T cell differentiation. Acts upstream of or within several processes, including cellular response to potassium ion starvation; gluconeogenesis; and glycerol biosynthetic process from pyruvate. Located in cytosol. Is expressed in several structures, including alimentary system; brown fat; liver; and urinary system. Human ortholog(s) of this gene implicated in Alzheimer's disease and type 2 diabetes mellitus. Orthologous to human PCK1 (phosphoenolpyruvate carboxykinase 1). [provided by Alliance of Genome Resources, Apr 2022]