(from Uniprot) Displays cellular triglyceride lipase activity in liver, increases the levels of intracellular fatty acids derived from the hydrolysis of newly formed triglyceride stores and plays a role in very low-density lipoprotein assembly. Displays serine esterase activity in liver. Deacetylates a variety of arylacetamide substrates, including xenobiotic compounds and procarcinogens, converting them to the primary arylamide compounds and increasing their toxicity (By similarity)
(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Deuterostomia: NE > Chordata: NE > Craniata: NE > Vertebrata: NE > Gnathostomata: NE > Teleostomi: NE > Euteleostomi: NE > Sarcopterygii: NE > Dipnotetrapodomorpha: NE > Tetrapoda: NE > Amniota: NE > Mammalia: NE > Theria: NE > Eutheria: NE > Boreoeutheria: NE > Euarchontoglires: NE > Glires: NE > Lagomorpha: NE > Leporidae: NE > Oryctolagus: NE > Oryctolagus cuniculus: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA GVKTVLLLIVGVLGAYYVYTPLPDNIEEPWRLLWVNAHMKTLTNLALFAE YLGSNIFMNTVKFLTSFQEVPPTSDENVTVTETTFNNVPVRVYVPKRKSK TLRRGLFYIHGGGWCVGSAALSGYDLLSRRTADRLDVVVVSTNYRLAPEY HFPIQFEDVYDALKWFLRQDVLEKYGVDPERVGVSGDSAGGNLAAAVAQQ LIKDPDVKIKLKTQSLIYPALQTLDMDLPSYRENAQFPILSKSFMVRLWS EYFTSDRSLEKAMLLNQHVPVESSHLFKFTNWSSLLPEKFKKGHVYNTPT YGSSELARKYPGFLDVRAAPLLADDAQLRGFPLTYVITCQYDVLRDDGVM YVTRLRNAGVQVTHNHIEDGFHGALSYNGFKTGYRVEKQYFEWLRENV
References
Title: Appropriate function of 11beta-hydroxysteroid dehydrogenase type 1 in the endoplasmic reticulum lumen is dependent on its N-terminal region sharing similar topological determinants with 50-kDa esterase Frick C, Atanasov AG, Arnold P, Ozols J, Odermatt A Ref: Journal of Biological Chemistry, 279:31131, 2004 : PubMed
By interconverting glucocorticoids, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) exerts an important pre-receptor function and is currently considered a promising therapeutic target. In addition, 11beta-HSD1 plays a potential role in 7-ketocholesterol metabolism. Here we investigated the role of the N-terminal region on enzymatic activity and addressed the relevance of 11beta-HSD1 orientation into the endoplasmic reticulum (ER) lumen. Previous studies revealed that the luminal orientation of 11beta-HSD1 and 50-kDa esterase/arylacetamide deacetylase (E3) is determined by their highly similar N-terminal transmembrane domains. Substitution of Lys(5) by Ser in 11beta-HSD1, but not of the analogous Lys(4) by Ile in E3, led to an inverted topology in the ER membrane, indicating the existence of a second topological determinant. Here we identified Glu(25)/Glu(26) in 11beta-HSD1 and Asp(25) in E3 as the second determinant for luminal orientation. Our results suggest that the exact location of specific residues rather than net charge distribution on either side of the helix is critical for membrane topology. Analysis of charged residues in the N-terminal domain revealed an essential role of Lys(35)/Lys(36) and Glu(25)/Glu(26) on enzymatic activity, suggesting that these residues are responsible for the observed stabilizing effect of the N-terminal membrane anchor on the catalytic domain of 11beta-HSD1. Moreover, activity measurements in intact cells expressing wild-type 11beta-HSD1, facing the ER lumen, or mutant K5S/K6S, facing the cytoplasm, revealed that the luminal orientation is essential for efficient oxidation of cortisol. Furthermore, we demonstrate that 11beta-HSD1, but not mutant K5S/K6S with cytoplasmic orientation, catalyzes the oxoreduction of 7-ketocholesterol. 11beta-HSD1 and E3 constructs with cytosolic orientation of their catalytic moiety should prove useful in future studies addressing the physiological function of these proteins.
Title: Targeting proteins to the lumen of endoplasmic reticulum using N-terminal domains of 11beta-hydroxysteroid dehydrogenase and the 50-kDa esterase Mziaut H, Korza G, Hand AR, Gerard C, Ozols J Ref: Journal of Biological Chemistry, 274:14122, 1999 : PubMed
Previous studies identified two intrinsic endoplasmic reticulum (ER) proteins, 11beta-hydroxysteroid dehydrogenase, isozyme 1 (11beta-HSD) and the 50-kDa esterase (E3), sharing some amino acid sequence motifs in their N-terminal transmembrane (TM) domains. Both are type II membrane proteins with the C terminus projecting into the lumen of the ER. This finding implied that the N-terminal TM domains of 11beta-HSD and E3 may constitute a lumenal targeting signal (LTS). To investigate this hypothesis we created chimeric fusions using the putative targeting sequences and the reporter gene, Aequorea victoria green fluorescent protein. Transfected COS cells expressing LTS-green fluorescent protein chimeras were examined by fluorescent microscopy and electron microscopic immunogold labeling. The orientation of expressed chimeras was established by immunocytofluorescent staining of selectively permeabilized COS cells. In addition, protease protection assays of membranes in the presence and absence of detergents was used to confirm lumenal or the cytosolic orientation of the constructed chimeras. To investigate the general applicability of the proposed LTS, we fused the N terminus of E3 to the N terminus of the NADH-cytochrome b5 reductase lacking the myristoyl group and N-terminal 30-residue membrane anchor. The orientation of the cytochrome b5 reductase was reversed, from cytosolic to lumenal projection of the active domain. These observations establish that an amino acid sequence consisting of short basic or neutral residues at the N terminus, followed by a specific array of hydrophobic residues terminating with acidic residues, is sufficient for lumenal targeting of single-pass proteins that are structurally and functionally unrelated.
Title: Determination of lumenal orientation of microsomal 50-kDa esterase/N-deacetylase Ozols J Ref: Biochemistry, 37:10336, 1998 : PubMed
The amino acid arrangements responsible for the insertion and specific lumenal orientation of proteins having an uncleaved signal-peptide-like anchor are poorly understood. A 50-kDa protein having a hydrophobic N-terminus similar to the lumenal glycoprotein 11beta-hydroxysteroid dehydrogenase [Ozols, J. (1995) J. Biol. Chem. 270, 2305-2312] was identified in detergent-solubilized microsomes. The posttranslational modifications and the membrane orientation of the 50-kDa protein were investigated using the approaches of protein structure analysis. Sequence analysis of the entire 50-kDa protein showed a lack of structural relatedness to the steroid dehydrogenase beyond the membrane binding segment. Structure analysis of peptides revealed that carbohydrate is attached at Asn-77 and Asn-281, implying that these sites of the 50-kDa protein are oriented toward the lumenal side of the endoplasmic membrane (ER). Specific enzymatic deglycosylation on the intact protein identified the two glycans as high mannose carbohydrate rather than of the complex type, suggesting that the protein had not undergone further trafficking steps beyond the lumen of ER. Chemical modification of cysteinyl residues showed a lack of free thiols in the intact protein. Peptide mapping identified one disulfide bond between Cys-115 and -340 further restricting the bulk of the protein to the lumenal compartment. Proteolysis of intact and solubilized microsomes showed that the 50-kDa protein is resistant to fragmentation at the conditions which led to the removal of the membranous segments from cytochrome b5 and the NADH-cytochrome b5 reductase. The proposed model of the 50-kDa protein predicts one transmembrane segment at the N-terminus, flanked by positively charged residues on the cytosolic surface and negatively charged residues on the lumenal side of the hydrophobic domain, with most of the polypeptide projecting into the lumen of the ER. The stated similarities in the topology between 11beta-steroid dehydrogenase and 50-kDa protein envision their transmembrane segment consisting of a basic residue(s) followed by an array of some 17 hydrophobic residues containing the Ala-Tyr-Tyr-X-Tyr cluster, where X represents a hydrophobic amino acid, which terminates with acidic residues. It is proposed here that such a motif may constitute a lumenal targeting signal for a set of single-membrane-spanning proteins that are otherwise structurally and functionally unrelated.
Oryctolagus cuniculus protein for liver 60 kD carboxylesterase 1