Enables ephrin receptor binding activity; potassium ion transmembrane transporter activity; and water transmembrane transporter activity. Involved in defense response to Gram-negative bacterium and potassium ion transport. Acts upstream of or within several processes, including corticotropin secretion; glomerular filtration; and metanephros development. Located in several cellular components, including basolateral plasma membrane; extracellular exosome; and symbiont-containing vacuole. Is integral component of membrane. Is expressed in several structures, including alimentary system; cardiovascular system; genitourinary system; sensory organ; and skeleton. Orthologous to human AQP1 (aquaporin 1 (Colton blood group)). [provided by Alliance of Genome Resources, Apr 2022]