Biomaterial Database

On the requirement for protein synthesis during corticotropin-induced stimulation of cholesterol side chain cleavage in rat adrenal mitochondrial and solubilized desmolase preparations. 1977

R V Farese, and W J Prudente

Following simple homogenization, significant amounts of mitochondrial-derived, cholesterol side chain cleaving enzyme (desmolase) activity are recovered in rat adrenal 105 000 X g-supernatant fraction. Corticotropin administration enhances soluble desmolase activity, and cycloheximide potentiates this effect. The lipid droplet fraction which has no desmolase activity markedly enhances pregnenolone synthesis in the soluble desmolase preparations, presumably by supplying free cholesterol substrate. Corticotropin particularly with cycloheximide pretreatment, enhances lipid fraction activity. Thus increased cholesterol availability may largely explain the corticotropin effect on the soluble desmolase system. Since protein synthesis is required for corticotropin activity in intact mitochondria, but not in calcium-swollen mitochondria or the soluble enzyme system, the labile protein apparently required during corticotropin action may function to overcome a "barrier" which exists only in the intact mitochondria and restrains cholesterol side chain cleavage.

UI	MeSH Term	Description	Entries
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D008933	Mitochondrial Swelling	An increase in MITOCHONDRIAL VOLUME due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria.	Giant Mitochondria,Megamitochondria,Mitochondrial Hypertrophy,Giant Mitochondrias,Hypertrophy, Mitochondrial,Megamitochondrias,Mitochondria, Giant,Mitochondrial Hypertrophies,Swelling, Mitochondrial
D010088	Oxidoreductases	The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)	Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002786	Cholesterol Side-Chain Cleavage Enzyme	A mitochondrial cytochrome P450 enzyme that catalyzes the side-chain cleavage of C27 cholesterol to C21 pregnenolone in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11A1 gene, catalyzes the breakage between C20 and C22 which is the initial and rate-limiting step in the biosynthesis of various gonadal and adrenal steroid hormones.	CYP11A1,Cholesterol Desmolase,Cholesterol Monooxygenase (Side-Chain-Cleaving),Cytochrome P-450 CYP11A1,Cytochrome P-450(scc),20,22-Desmolase,CYP 11A1,Cytochrome P450 11A1,Cytochrome P450scc,20,22 Desmolase,Cholesterol Side Chain Cleavage Enzyme,Cytochrome P 450 CYP11A1
D003513	Cycloheximide	Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.	Actidione,Cicloheximide
D000311	Adrenal Glands	A pair of glands located at the cranial pole of each of the two KIDNEYS. Each adrenal gland is composed of two distinct endocrine tissues with separate embryonic origins, the ADRENAL CORTEX producing STEROIDS and the ADRENAL MEDULLA producing NEUROTRANSMITTERS.	Adrenal Gland,Gland, Adrenal,Glands, Adrenal
D000324	Adrenocorticotropic Hormone	An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).	ACTH,Adrenocorticotropin,Corticotropin,1-39 ACTH,ACTH (1-39),Adrenocorticotrophic Hormone,Corticotrophin,Corticotrophin (1-39),Corticotropin (1-39),Hormone, Adrenocorticotrophic,Hormone, Adrenocorticotropic
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
D014176	Protein Biosynthesis	The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.	Genetic Translation,Peptide Biosynthesis, Ribosomal,Protein Translation,Translation, Genetic,Protein Biosynthesis, Ribosomal,Protein Synthesis, Ribosomal,Ribosomal Peptide Biosynthesis,mRNA Translation,Biosynthesis, Protein,Biosynthesis, Ribosomal Peptide,Biosynthesis, Ribosomal Protein,Genetic Translations,Ribosomal Protein Biosynthesis,Ribosomal Protein Synthesis,Synthesis, Ribosomal Protein,Translation, Protein,Translation, mRNA,mRNA Translations