Page last updated: 2024-10-24
rod photoreceptor outer segment
Definition
Target type: cellularcomponent
The outer segment of a vertebrate rod photoreceptor that contains sealed membrane discs that are not connected to the ciliary membrane and containing rhodopsin photoreceptor proteins. [GOC:krc, GOC:pde, PMID:19501669, PMID:26574505, PMID:6771304]
The rod photoreceptor outer segment is a highly specialized cellular compartment responsible for light detection in the retina. It is comprised of numerous stacked membrane discs, which are derived from the plasma membrane and contain the light-sensitive photopigment rhodopsin. These discs are arranged in a highly ordered manner, with the outer segment being surrounded by a plasma membrane. The outer segment is connected to the inner segment of the rod cell via a structure called the connecting cilium. This connection serves as a pathway for the transport of proteins, lipids, and other essential molecules between the inner and outer segments. The outer segment is also characterized by a high density of mitochondria, which provide energy for phototransduction and other cellular processes. The outer segment is constantly being renewed through a process called disc shedding, where the oldest discs are shed from the tip of the outer segment and are phagocytized by retinal pigment epithelial cells. The outer segment is also a highly dynamic structure, with its shape and size changing in response to light stimulation. These changes are regulated by a complex interplay of molecular signaling pathways and are essential for the process of phototransduction.'
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Proteins (3)
| Protein | Definition | Taxonomy |
|---|---|---|
| cGMP-gated cation channel alpha-1 | A cGMP-gated cation channel alpha-1 that is encoded in the genome of cow. [OMA:Q00194, PRO:DNx] | Bos taurus (cattle) |
| Rhodopsin | A rhodopsin that is encoded in the genome of cow. [OMA:P02699, PRO:DNx] | Bos taurus (cattle) |
| Sodium/potassium-transporting ATPase subunit alpha-4 | A sodium/potassium-transporting ATPase subunit alpha-4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q13733] | Homo sapiens (human) |
Compounds (15)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| lansoprazole | Lansoprazole: A 2,2,2-trifluoroethoxypyridyl derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. Lansoprazole is a racemic mixture of (R)- and (S)-isomers. | benzimidazoles; pyridines; sulfoxide | anti-ulcer drug; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor |
| omeprazole | 5-methoxy-2-{[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl}-1H-benzimidazole : A member of the class of benzimidazoles that is 1H-benzimidazole which is substituted by a [4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl group at position 2 and a methoxy group at position 5. omeprazole : A racemate comprising equimolar amounts of (R)- and (S)-omeprazole. Omeprazole: A 4-methoxy-3,5-dimethylpyridyl, 5-methoxybenzimidazole derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits an H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. | aromatic ether; benzimidazoles; pyridines; sulfoxide | |
| pantoprazole | pantoprazole : A member of the class of benzimidazoles that is 1H-benzimidazole substituted by a difluoromethoxy group at position 5 and a [(3,4-dimethoxypyridin-2-yl)methyl]sulfinyl group at position 2. Pantoprazole: 2-pyridinylmethylsulfinylbenzimidazole proton pump inhibitor that is used in the treatment of GASTROESOPHAGEAL REFLUX and PEPTIC ULCER. | aromatic ether; benzimidazoles; organofluorine compound; pyridines; sulfoxide | anti-ulcer drug; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor; environmental contaminant; xenobiotic |
| tetracaine | tetracaine : A benzoate ester in which 4-N-butylbenzoic acid and 2-(dimethylamino)ethanol have combined to form the ester bond; a local ester anaesthetic (ester caine) used for surface and spinal anaesthesia. Tetracaine: A potent local anesthetic of the ester type used for surface and spinal anesthesia. | benzoate ester; tertiary amino compound | local anaesthetic |
| madecassic acid | monocarboxylic acid; pentacyclic triterpenoid; tetrol | antioxidant; plant metabolite | |
| rostafuroxin | rostafuroxin: structure in first source | ||
| nsc 88915 | 4-pregnen-21-ol-3,20-dione-21-(4-bromobenzenesufonate): a tyrosyl-DNA phosphodiesterase inhibitor; structure in first source | ||
| ouabain | cardiac glycoside : Steroid lactones containing sugar residues that act on the contractile force of the cardiac muscles. ouabain : A steroid hormone that is a multi-hydroxylated alpha-L-rhamnosyl cardenoloide. It binds to and inhibits the plasma membrane Na(+)/K(+)-ATPase (sodium pump). It has been isolated naturally from Strophanthus gratus. Ouabain: A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE. | 11alpha-hydroxy steroid; 14beta-hydroxy steroid; 5beta-hydroxy steroid; alpha-L-rhamnoside; cardenolide glycoside; steroid hormone | anti-arrhythmia drug; cardiotonic drug; EC 2.3.3.1 [citrate (Si)-synthase] inhibitor; EC 3.1.3.41 (4-nitrophenylphosphatase) inhibitor; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor; EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor; ion transport inhibitor; plant metabolite |
| digitoxin | digitoxin : A cardenolide glycoside in which the 3beta-hydroxy group of digitoxigenin carries a 2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1->4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1->4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl trisaccharide chain. Digitoxin: A cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting. (From Martindale, The Extra Pharmacopoeia, 30th ed, p665) | cardenolide glycoside | EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor |
| digoxin | digoxin : A cardenolide glycoside that is digitoxin beta-hydroxylated at C-12. A cardiac glycoside extracted from the foxglove plant, Digitalis lanata, it is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation, but the margin between toxic and therapeutic doses is small. Digoxin: A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666) | cardenolide glycoside; steroid saponin | anti-arrhythmia drug; cardiotonic drug; EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor; epitope |
| digitoxigenin | digitoxigenin : A 5beta-cardenolide that is 5beta-cardanolide with hydroxy substituents at the 3beta- and 14beta-positions and double bond unsaturation at C(20)-C(22). Digitoxigenin: 3 beta,14-Dihydroxy-5 beta-card-20(22)enolide. A cardenolide which is the aglycon of digitoxin. Synonyms: Cerberigenin; Echujetin; Evonogenin; Thevetigenin. | 14beta-hydroxy steroid; 3beta-hydroxy steroid | |
| phakellistatin 2 | phakellistatin 2: isolated from the marine sponge Phakellia carteri; structure in first source | ||
| digitoxigenin monodigitoxoside | digitoxigenin monodigitoxoside: RN given refers to (ribo-3beta,5beta)-isomer | ||
| evomonoside | evomonoside : A cardenolide glycoside consisting of digitoxigenin having an alpha-L-rhamnosyl moiety attached at the O(3)-position. evomonoside: a cytotoxic cardiac glycoside from Lepidium apetalum; RN refers to (3beta,5beta)-isomer | cardenolide glycoside | |
| halisulfate 1 | halisulfate 1: an isocitrate lyase inhibitor sesterterpene sulfate from sponge, Hippospongia sp.; structure in first source | organic molecular entity | metabolite |