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Endothelin-converting enzyme-1 (ECE-1) is a type II membrane protein that catalyzes the proteolytic activation of big endothelin-1 to endothelin-1 (ET-1). The subcellular distribution of ECE-1, and hence the exact site of physiological activation of big ET-1, remains controversial. Here, we demonstrate with several complementary methods that the two alternatively spliced bovine ECE-1 isoforms, ECE-1a and ECE-1b, differing only in the first 30 amino acids of their N-terminal cytoplasmic tails, exhibit strikingly distinct intracellular sorting patterns. Bovine ECE-1a, which is responsible for the intracellular cleavage of big ET-1 in endothelial cells, is constitutively recruited into the lysosome, where it is rapidly degraded. In contrast, bovine ECE-1b, the isoform found in cultured smooth muscle cells, is transported to the plasma membrane by a default pathway and functions as an ectoenzyme. Mutational analyses reveal that the N-terminal tip of the cytoplasmic domain of bovine ECE-1a contains novel proline-containing signals that mediate constitutive lysosomal targeting. Analyses of chimeric ECE-1/transferrin receptors demonstrate that the cytoplasmic tail of bovine ECE-1a is sufficient for the lysosomal delivery and rapid degradation. Our results suggest that the distinct intracellular targeting of bovine ECE-1 isoforms may provide new insights into functional aspect of the endothelin system and that the cell permeability of ECE inhibitor compounds should be carefully considered during their pharmacological development.The endothelins are a family of 21-amino acid peptides consisting of three closely related isoforms termed endothelin-1 (ET-1), 1 ET-2, and ET-3 (1, 2). They act on two molecularly distinct subtypes of seven membrane-spanning G protein-coupled receptors, the endothelin A (ET A ) and endothelin B (ET B ) receptors, to mediate a wide variety of biological activities (3, 4). Recent studies with specific endothelin receptor antagonists have illustrated important roles of endothelins in a number of pathological conditions in humans including congestive heart failure, vascular restenosis, and essential hypertension (5-9). Further, recent genetic studies in mice demonstrated that the endothelin system is also required for development of specific neural crest-derived tissues (10 -13).Biologically active endothelins are produced from prepropolypeptides through two steps of proteolytic processing. The approximately 200-residue preproendothelins are first processed by a furin-like processing protease(s) into biologically inactive intermediates termed big endothelins (big ETs). These are then proteolytically cleaved between Trp 21 and Val/Ile 22 to produce active endothelins. This proteolytic conversion is catalyzed by specific endothelin-converting enzymes (ECEs). Two isozymes of ECE, ECE-1 and ECE-2, have been molecularly identified (14 -16). Both ECEs are type II membrane proteins with highly conserved Zn 2ϩ metalloprotease motifs and cleave big ET-1 to produce ET-1 in vitro as well as in transfected cel...

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AbstrakLatar belakang: Adanya kekuatiran tingginya risiko negatif terhadap kesehatan teknisi, mahasiswa dan staf yang terlibat dalam pemrosesan dan penggunaan preparat cadaver anatomi yang selama ini lebih sering menggunakan larutan pengawet dengan formalin kadar tinggi (37% formaldehyde). Dirasakan perlu pengenalan teknik pengawetan cadaver yang aman, efektif dan efisien, dengan efek risiko yang lebih rendah terhadap kesehatan yaitu dengan menggunakan larutan pengawet dengan formalin kadar rendah (5-7,5% formaldehyde) yang akan diuraikan lebih lanjut dalam naskah ini.Metode: Cadaver anatomi diinjeksi dengan menggunakan larutan pengawet berisi formalin kadar rendah (5-7. AbstractBackground: We used cadaver embalming technique with a high concentration of formaldehyde (37% formaldehyde). However, it gives toxic effects which can endanger the technicians, lecturers and students. For that reason, the effective, efficient and safer embalming process is needed; in this article we describe the use of low formalin solution (5-7.5% formaldehyde) to achieve prior purposes.Methods: Cadaver is embalmed by actively pumping low formalin-containing solution (5-7.5%) via femoral arteries. Further methods are detailed in this manuscript.Results: Paler cadaver with more intact and easier to dissect specimen (drier and still moist with no fungal growth) was resulted by using this low formalin technique. Conclusion:The use of low formalin-containing solution in cadaver embalming gave good quality results for anatomy teaching. (Med J Indones. 2012;21:203-7)