sterol transport
Definition
Target type: biologicalprocess
The directed movement of sterols into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. Sterols are steroids with one or more hydroxyl groups and a hydrocarbon side-chain in the molecule. [GOC:ai]
Sterol transport is a fundamental biological process that ensures the proper distribution and utilization of sterols, essential lipids that play vital roles in cell membranes, hormone synthesis, and other cellular functions. This complex process involves a coordinated interplay of proteins, enzymes, and cellular structures, encompassing multiple steps from synthesis to delivery to final destination.
The journey of sterols begins with their biosynthesis in the endoplasmic reticulum (ER), where enzymes convert precursors into cholesterol, the most abundant sterol in animals. From the ER, newly synthesized sterols are packaged into transport vesicles that bud off and travel to the Golgi apparatus. Here, sterols undergo further modification and sorting, ultimately being loaded into specific carrier proteins for delivery to various cellular compartments.
One critical player in sterol transport is the sterol regulatory element-binding protein (SREBP), a transcription factor that regulates the expression of genes involved in sterol biosynthesis and uptake. When cellular sterol levels are low, SREBP is activated and translocates to the nucleus, where it binds to specific DNA sequences and stimulates the production of enzymes involved in sterol synthesis.
Beyond the ER and Golgi, sterols are transported to other cellular destinations, including the plasma membrane, lysosomes, and mitochondria. This movement relies on a diverse array of protein carriers, each tailored to specific sterols and cellular compartments. For instance, the Niemann-Pick C1 (NPC1) protein facilitates the transport of cholesterol from the late endosomes/lysosomes to the plasma membrane, while the ATP-binding cassette (ABC) transporters mediate the efflux of cholesterol from cells.
The precise mechanisms of sterol transport remain under investigation, but it is clear that this process is tightly regulated to maintain cellular homeostasis. Disruptions in sterol transport can lead to various diseases, including atherosclerosis, Niemann-Pick disease, and Smith-Lemli-Opitz syndrome. These conditions highlight the importance of sterol transport in human health.
In summary, sterol transport is a multifaceted and essential process involving the synthesis, modification, and delivery of sterols within cells. This intricate choreography ensures the appropriate distribution of these vital lipids, supporting diverse cellular functions and maintaining overall health.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| Microsomal triglyceride transfer protein large subunit | A microsomal triglyceride transfer protein large subunit that is encoded in the genome of human. [PRO:HJD, UniProtKB:P55157] | Homo sapiens (human) |
| Translocator protein | [no definition available] | Homo sapiens (human) |
Compounds (39)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| pk 11195 | PK-11195 : A monocarboxylic acid amide obtained by formal condensation of the carboxy group of 1-(2-chlorophenyl)isoquinoline-3-carboxylic acid with the amino group of sec-butylmethylamine | aromatic amide; isoquinolines; monocarboxylic acid amide; monochlorobenzenes | antineoplastic agent |
| ro 5-4864 | 4'-chlorodiazepam: selectively binds peripheral benzodiazepine receptor | ||
| clonazepam | clonazepam : 1,3-Dihydro-2H-1,4-benzodiazepin-2-one in which the hydrogens at positions 5 and 7 are substituted by 2-chlorophenyl and nitro groups, respectively. It is used in the treatment of all types of epilepsy and seizures, as well as myoclonus and associated abnormal movements, and panic disorders. However, its use can be limited by the development of tolerance and by sedation. Clonazepam: An anticonvulsant used for several types of seizures, including myotonic or atonic seizures, photosensitive epilepsy, and absence seizures, although tolerance may develop. It is seldom effective in generalized tonic-clonic or partial seizures. The mechanism of action appears to involve the enhancement of GAMMA-AMINOBUTYRIC ACID receptor responses. | 1,4-benzodiazepinone; monochlorobenzenes | anticonvulsant; anxiolytic drug; GABA modulator |
| nordazepam | nordazepam : A 1,4-benzodiazepinone having phenyl and chloro substituents at positions 5 and 7 respectively; it has anticonvulsant, anxiolytic, muscle relaxant and sedative properties but is used primarily in the treatment of anxiety. Nordazepam: An intermediate in the metabolism of DIAZEPAM to OXAZEPAM. It may have actions similar to those of diazepam. | 1,4-benzodiazepinone; organochlorine compound | anticonvulsant; anxiolytic drug; GABA modulator; human metabolite; sedative |
| diazepam | diazepam : A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one substituted by a chloro group at position 7, a methyl group at position 1 and a phenyl group at position 5. Diazepam: A benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a long duration of action. Its actions are mediated by enhancement of GAMMA-AMINOBUTYRIC ACID activity. | 1,4-benzodiazepinone; organochlorine compound | anticonvulsant; anxiolytic drug; environmental contaminant; sedative; xenobiotic |
| flunitrazepam | flunitrazepam : A 1,4-benzodiazepinone that is nitrazepam substituted by a methyl group at position 1 and by a fluoro group at position 2'. It is a potent hypnotic, sedative, and amnestic drug used to treat chronic insomnia. Flunitrazepam: A benzodiazepine with pharmacologic actions similar to those of DIAZEPAM that can cause ANTEROGRADE AMNESIA. Some reports indicate that it is used as a date rape drug and suggest that it may precipitate violent behavior. The United States Government has banned the importation of this drug. | 1,4-benzodiazepinone; C-nitro compound; monofluorobenzenes | anxiolytic drug; GABAA receptor agonist; sedative |
| lorazepam | Lorazepam: A benzodiazepine used as an anti-anxiety agent with few side effects. It also has hypnotic, anticonvulsant, and considerable sedative properties and has been proposed as a preanesthetic agent. | benzodiazepine | |
| nevirapine | nevirapine : A dipyridodiazepine that is 5,11-dihydro-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepine which is substituted by methyl, oxo, and cyclopropyl groups at positions 4, 6, and 11, respectively. A non-nucleoside reverse transcriptase inhibitor with activity against HIV-1, it is used in combination with other antiretrovirals for the treatment of HIV infection. Nevirapine: A potent, non-nucleoside reverse transcriptase inhibitor used in combination with nucleoside analogues for treatment of HIV INFECTIONS and AIDS. | cyclopropanes; dipyridodiazepine | antiviral drug; HIV-1 reverse transcriptase inhibitor |
| nitrazepam | nitrazepam : A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one which is substituted at positions 5 and 7 by phenyl and nitro groups, respectively. It is used as a hypnotic for the short-term management of insomnia and for the treatment of epileptic spasms in infants (West's syndrome). Nitrazepam: A benzodiazepine derivative used as an anticonvulsant and hypnotic. | 1,4-benzodiazepinone; C-nitro compound | anticonvulsant; antispasmodic drug; drug metabolite; GABA modulator; sedative |
| cm 7116 | norflutoprazepam: structure | benzodiazepine | |
| oxazepam | oxazepam : A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one substituted by a chloro group at position 7, a hydroxy group at position 3 and phenyl group at position 5. Oxazepam: A benzodiazepine used in the treatment of anxiety, alcohol withdrawal, and insomnia. | 1,4-benzodiazepinone; organochlorine compound | anxiolytic drug; environmental contaminant; xenobiotic |
| temazepam | Temazepam: A benzodiazepine that acts as a GAMMA-AMINOBUTYRIC ACID modulator and anti-anxiety agent. | benzodiazepine | |
| chlordesmethyldiazepam | benzodiazepine | ||
| halazepam | halazepam: structure | organic molecular entity | |
| alpidem | imidazoles | ||
| efavirenz | efavirenz : 1,4-Dihydro-2H-3,1-benzoxazin-2-one substituted at the 4 position by cyclopropylethynyl and trifluoromethyl groups (S configuration) and at the 6 position by chlorine. A non-nucleoside reverse transcriptase inhibitor with activity against HIV, it is used with other antiretrovirals for combination therapy of HIV infection. efavirenz: HIV-1 reverse transcriptase inhibitor | acetylenic compound; benzoxazine; cyclopropanes; organochlorine compound; organofluorine compound | antiviral drug; HIV-1 reverse transcriptase inhibitor |
| n-desmethylflunitrazepam | |||
| 7-aminonitrazepam | 7-aminonitrazepam: urinary metabolite of nitrazepam | benzodiazepine | |
| ro 20-1815 | 7-aminoflunitrazepam: flunitrazepam metabolite; structure given in first source | benzodiazepine | |
| dx 9065 | |||
| ro 11-6893 | Ro 11-6893: RN given refers to (R)-isomer | ||
| n,n-di-n-hexyl-2-(4-fluorophenyl)indole-3-acetamide | N,N-di-n-hexyl-2-(4-fluorophenyl)indole-3-acetamide: binds with high affinity to glial mitochondrial diazepam binding inhibitor receptors & increases mitochondrial steroidogenesis | phenylindole | |
| 7-aminoclonazepam | benzodiazepine | ||
| ro 5-3438 | Ro 5-3438: structure | ||
| n-desmethylflunitrazepam | N-desmethylflunitrazepam: metabolite of flunitrazepam | ||
| ro 05-4082 | ID 690: methyl deriv of clonazepam; structure | ||
| ac-5216 | |||
| cb 34 | CB 34: ligand for peripheral benzodiazepine receptors; structure in first source | ||
| n-(2-methoxybenzyl)-n-(4-phenoxypyridin-3-yl)acetamide | N-(2-methoxybenzyl)-N-(4-phenoxypyridin-3-yl)acetamide: for imaging brain peripheral benzodiazepine receptors; structure in first source | ||
| bms201038 | BMS201038: an anticholesteremic agent and microsomal triglycide transfer protein inhibitor lomitapide : A member of the class of benzamides obtained by formal condensation of the carboxy group of 4'-(trifluoromethyl)biphenyl-2-carboxylic acid with the primary amino group of 9-[4-(4-aminopiperidin-1-yl)butyl]-N-(2,2,2-trifluoroethyl)-9H-fluorene-9-carboxamide. Used (as its mesylate salt) as a complement to a low-fat diet and other lipid-lowering treatments in patients with homozygous familial hypercholesterolemia. | (trifluoromethyl)benzenes; benzamides; fluorenes; piperidines | anticholesteremic drug; MTP inhibitor |
| dirlotapide | dirlotapide: structure in first source | ||
| ssr180575 | SSR180575: structure in first source | ||
| daa 1106 | |||
| naluzotan | naluzotan: an antidepressant and anti-anxiety agent; structure in first source | ||
| dpa-713 | |||
| a 803467 | A 803467: an Nav1.8 sodium channel blocker; structure in first source | ||
| jnj-31020028 | |||
| n-fluoroacetyl-n-(2,5-dimethoxybenzyl)-2-phenoxyaniline | N-fluoroacetyl-N-(2,5-dimethoxybenzyl)-2-phenoxyaniline: a peripheral benzodiazepine receptor PET ligand; structure in first source | ||
| MS-417 | MS-417 : A member of the class of thienotriazolodiazepines that is the methyl ester of [(6S)-4-(4-chlorophenyl)-2,3,9-trimethyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepin-6-yl]acetic acid. A bromodomain and extra-terminal domain (BET)-specific inhibitor that belongs to a group of thienodiazepine-based compounds | methyl ester; monochlorobenzenes; thienotriazolodiazepine |