Biomaterial Database

Retinol esterification by mouse epidermal microsomes: evidence for acyl-CoA:retinol acyltransferase activity. 1987

H Törmä, and A Vahlquist

In an attempt to characterize the enzyme(s) responsible for retinol esterification in hairless mouse epidermis, various subcellular fractions were incubated with [3H]retinol and the reaction products (retinyl esters) isolated by high-performance liquid chromatography. The microsomal fraction exhibited the highest esterifying activity and was stimulated by the addition of palmitoyl-CoA and dithiothreitol, but not by palmitic acid. Saturation kinetics with an apparent Km of about 6 microM for retinol were noted. Experiments with competitive and noncompetitive inhibitors of [3H]retinol esterification established that the epidermal enzyme was an acyl-CoA:retinol acyltransferase (ARAT; EC 2.3.1.76). The specificity for retinol was not absolute; a few closely related vitamin A alcohols were equally good substrates. The ARAT activity was not significantly altered by physiologic variations in the epidermal vitamin A content. In conclusion, mouse epidermis expresses ARAT activity which may be of importance for the regulation of vitamin A metabolism at the cellular level.

UI	MeSH Term	Description	Entries
D008861	Microsomes	Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Microsome
D004224	Diterpenes	Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.	Diterpene,Diterpenes, Cembrane,Diterpenes, Labdane,Diterpenoid,Labdane Diterpene,Norditerpene,Norditerpenes,Norditerpenoid,Cembranes,Diterpenoids,Labdanes,Norditerpenoids,Cembrane Diterpenes,Diterpene, Labdane,Labdane Diterpenes
D004817	Epidermis	The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of EPITHELIUM: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis).
D004952	Esters	Compounds derived from organic or inorganic acids in which at least one hydroxyl group is replaced by an –O-alkyl or another organic group. They can be represented by the structure formula RCOOR’ and are usually formed by the reaction between an acid and an alcohol with elimination of water.	Ester
D000084562	Retinyl Esters	A carboxylic ester of retinol formed by condensation of the hydroxy group of retinol with a carboxy group.	All-Trans-Retinyl Ester,All-Trans-Retinyl Esters,Retinyl Ester,All Trans Retinyl Ester,All Trans Retinyl Esters,Ester, All-Trans-Retinyl,Ester, Retinyl
D000217	Acyltransferases	Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.	Acyltransferase
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D014801	Vitamin A	Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.	Retinol,11-cis-Retinol,3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraen-1-ol, (all-E)-Isomer,All-Trans-Retinol,Aquasol A,Vitamin A1,All Trans Retinol
D051142	Retinol O-Fatty-Acyltransferase	An enzyme that catalyzes the acyl group transfer of acyl COENZYME A to RETINOL to generate COENZYME A and a retinyl ester.	Acyl CoA-Retinol Acyltransferase,Fatty Acyl Coenzyme A-Retinol Acyltransferase,Retinol Ester Synthetase,Retinol Fatty-Acyltransferase,Retinol Stearate Synthetase,Retinol-Palmitate Synthetase,Acyl CoA Retinol Acyltransferase,Acyltransferase, Acyl CoA-Retinol,CoA-Retinol Acyltransferase, Acyl,Ester Synthetase, Retinol,Fatty Acyl Coenzyme A Retinol Acyltransferase,Fatty-Acyltransferase, Retinol,O-Fatty-Acyltransferase, Retinol,Retinol Fatty Acyltransferase,Retinol O Fatty Acyltransferase,Retinol Palmitate Synthetase,Stearate Synthetase, Retinol,Synthetase, Retinol Ester,Synthetase, Retinol Stearate,Synthetase, Retinol-Palmitate