Involved in cell size determination. Expressed in flowers and stems. Barely detectable in 6 days after-germination (DAG) seedlings, but highly expressed in 14 DAG seedlings. The BURP domain located at the C-terminus has not been identified in non-plant proteins. No visible phenotype. Atpgl1, atpgl2 and atpgl3 triple mutants produce smaller leaves and petioles.