Characterization of the first angiotensin-converting like enzyme in bacteria: Ancestor ACE is already active

Abstract

Angiotensin-converting enzyme (ACE) is a metallopeptidase that converts angiotensin I into angiotensin II. ACE is crucial in the control of cardiovascular and renal homeostasis and fertility in mammals. In vertebrates, both transmembrane and soluble ACE, containing one or two active sites, have been characterized. So far, only soluble, single domain ACEs from invertebrates have been cloned, and these have been implicated in reproduction in insects. Furthermore, an ACE-related carboxypeptidase was recently characterized in Leishmania, a unicellular eukaryote, suggesting the existence of ACE in more distant organisms. Interestingly, in silico databank analysis revealed that bacterial DNA sequences could encode putative ACE-like proteins, strikingly similar to vertebrates' enzymes. To gain more insight into the bacterial enzymes, we cloned the putative ACE from the phytopathogenic bacterium, Xanthomonas axonopodis pv. citri, named XcACE. The 2 kb open reading frame encodes a 672-amino-acid soluble protein containing a single active site. In vitro expression and biochemical characterization revealed that XcACE is a functional 72 kDa dipeptidyl-carboxypeptidase. As in mammals, this metalloprotease hydrolyses angiotensin I into angiotensin II. XcACE is sensitive to ACE inhibitors and chloride ions concentration. Variations in the active site residues, highlighted by structural modelling, can account for the different substrate selectivity and inhibition profile compared to human ACE. XcACE characterization demonstrates that ACE is an ancestral enzyme, provoking questions about its appearance and structure/activity specialisation during the course of evolution.

A Crucial Role in Fertility for the Oyster Angiotensin-Converting Enzyme Orthologue CgACE

“…labial palps, gills and digestive gland. This expression pattern likely reflects a digestive and unspecialized role of the enzyme, like already speculated for ACE orthologues in all the other metazoan organisms in which ACE expression was examined [31], [49]. Consistently, the greatest amounts of Cg ACE mRNA during oyster development are observed just before the metamorphosis when the animals undergo morpho-physiological changes implicating a degradation of many cell proteins.…”

“…Regardless of this point, the presence of ACE in oysters is consistent with the presence of ACE orthologues throughout the animal kingdom [30], [31]. However, the biological function(s) of such orthologues has never been addressed outside Vertebrates and Ecdysozoans, despite being of interest for the understanding of the evolution of enzyme/substrates systems.…”

Angiotensin‐converting enzyme 2 (ACE2) expression and activity in human carotid atherosclerotic lesions

“…Immunohistochemistry of ACE2 and ACE was performed on sections from human vena cava ( n = 5), non‐diseased mammary arteries ( n = 5) or carotid arteries containing an early ( n = 6), stable advanced lesion ( n = 7) or a lesion with a thrombus ( n = 5), as described previously 4. Paraffin‐embedded sections were stained with primary antibodies against rabbit anti‐ACE2 (1 : 1250; Clone 83M, Millenium Pharmaceuticals) 4 or sheep anti‐ACE (1 : 500) 10. Staining was visualized as a brown precipitate using 3,3′‐diamonobenzidine tetrachloride (DAB).…”

Regulation of cell volume and water transport – An old fundamental role of the renin angiotensin aldosterone system components at the cellular level

“…Also, an asparyl protease of 32 kDa exhibiting 35% of sequence identity with mammalian renin, has been found in the leech [28,30]. Biochemically, renin, ACE-and AT1-like receptor were identified in the leech immune cells [28] and ACE has been found in bacteria [26]. So far, only soluble, single domain ACEs from invertebrates have been cloned, and these have been implicated in reproduction in insects [18].…”