Loss of angiotensin-converting enzyme-related (ACER) peptidase disrupts behavioural and metabolic responses to diet in .

() encodes a member of the angiotensin-converting enzyme (ACE) family of metallopeptidases that in mammals play roles in the endocrine regulation of blood homeostasis. ACE is also expressed in adipose tissue, where it is thought to play a role in metabolic regulation. ACER is expressed in the adult fat body of the head and abdomen and is secreted into the haemolymph. null mutants have previously been found to have reduced night-time sleep and greater sleep fragmentation. ACER may thus be part of a signalling system linking metabolism with sleep. To further understand the role of ACER in response to diet, we measured sleep and other nutrient-responsive phenotypes in null flies under different dietary conditions. We show that loss of Acer disrupts the normal response of sleep to changes in nutrition. Other nutrient-sensitive phenotypes, including survival and glycogen storage, were also altered in the mutant but lipid storage was not. Although the physiological substrate of the ACER peptidase has not been identified, an alteration of the normal nutrient-dependent control of insulin-like peptide 5 protein in the mutant suggests insulin/IGF-like signalling as a candidate pathway modulated by ACER in the nutrient-dependent control of sleep, survival and metabolism.