Target type: biologicalprocess
The series of molecular signals mediated by the detection of a hormone, and which triggers the apoptotic signaling pathway in a cell. The pathway starts with reception of a hormone signal, and ends when the execution phase of apoptosis is triggered. [GOC:bf, GOC:mtg_apoptosis]
Hormone-mediated apoptotic signaling pathways are intricate cellular processes that involve the precise coordination of molecular events triggered by the binding of hormones to their specific receptors. This cascade of events ultimately leads to programmed cell death, or apoptosis, a crucial mechanism for maintaining tissue homeostasis and eliminating damaged or unwanted cells.
The pathway begins with the binding of a hormone to its receptor, typically located on the cell surface. This interaction initiates a signaling cascade that involves a series of intracellular messengers and enzymes. For example, steroid hormones, such as cortisol and estrogen, can bind to intracellular receptors that translocate to the nucleus and regulate gene expression. Other hormones, such as growth factors and cytokines, activate cell surface receptors that activate downstream signaling pathways, often involving protein kinases.
Several key signaling pathways are commonly involved in hormone-mediated apoptosis. The most well-characterized is the extrinsic pathway, which is initiated by the binding of death ligands, such as tumor necrosis factor-alpha (TNF-α), to their respective death receptors. This interaction triggers the recruitment of adaptor proteins, which activate caspase-8, a key protease involved in the apoptotic cascade. Caspase-8 can then cleave and activate caspase-3, the executioner caspase, leading to the dismantling of the cell.
The intrinsic pathway, also known as the mitochondrial pathway, is activated by various cellular stresses, such as DNA damage, oxidative stress, and nutrient deprivation. These stresses activate pro-apoptotic proteins, such as Bax and Bak, which promote the release of cytochrome c from mitochondria into the cytosol. Cytochrome c interacts with Apaf-1, forming the apoptosome, a protein complex that activates caspase-9. Caspase-9, in turn, activates caspase-3, leading to the initiation of apoptosis.
The convergence of these pathways at the level of caspase-3 highlights the intricate regulatory network involved in hormone-mediated apoptosis. Both extrinsic and intrinsic pathways ultimately lead to the activation of caspase-3, resulting in the cleavage of numerous cellular proteins and the dismantling of the cell.
Hormone-mediated apoptotic signaling pathways are crucial for maintaining cellular homeostasis and eliminating unwanted or damaged cells. Dysregulation of these pathways can contribute to various diseases, including cancer and autoimmune disorders. Understanding the intricacies of these pathways is essential for developing targeted therapies for these conditions.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Somatostatin receptor type 3 | A somatostatin receptor type 3 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P32745] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| astemizole | astemizole : A piperidine compound having a 2-(4-methoxyphenyl)ethyl group at the 1-position and an N-[(4-fluorobenzyl)benzimidazol-2-yl]amino group at the 4-position. Astemizole: Antihistamine drug now withdrawn from the market in many countries because of rare but potentially fatal side effects. | benzimidazoles; piperidines | anti-allergic agent; anticoronaviral agent; H1-receptor antagonist |
| camptothecin | NSC 100880: carboxylate (opened lactone) form of camptothecin; RN refers to (S)-isomer; structure given in first source | delta-lactone; pyranoindolizinoquinoline; quinoline alkaloid; tertiary alcohol | antineoplastic agent; EC 5.99.1.2 (DNA topoisomerase) inhibitor; genotoxin; plant metabolite |
| edotreotide | Edotreotide: DOTA - 1,4,7,10-tetraazacyclododecanetetracetic acid; structure given in first source; may be labelled with various radioisotopes | ||
| l803087 | L-803087 : A fluoroindole that is 1H-indole substituted by phenyl, 4-{[(2S)-5-carbamimidamido-1-methoxy-1-oxopentan-2-yl]amino}-4-oxobutyl, fluoro and fluoro groups at positions 2, 3, 5 and 7, respectively. It is a selective nonpeptidic agonist of the somatostatin subtype-4 (SST4) receptor with Ki of 0.7 nM. L803087: structure in first source | benzenes; fluoroindole; guanidines; L-arginine derivative; methyl ester; phenylindole; secondary carboxamide | somatostatin receptor agonist |
| obelin | obelin: calcium-sensitive photoprotein obtained from the hydroid Obelia geniculata | ||
| seglitide | seglitide: more potent than somatostatin for inhibition of insulin, glucagon & growth hormone release; used experimentally in treatment of Alzheimer's disease; somatostatin receptor antagonist | ||
| lanreotide | |||
| l 363301 | |||
| pasireotide | pasireotide : A six-membered homodetic cyclic peptide composed from L-phenylglycyl, D-tryptophyl, L-lysyl, O-benzyl-L-tyrosyl, L-phenylalanyl and modified L-hydroxyproline residues joined in sequence. A somatostatin analogue with pharmacologic properties mimicking those of the natural hormone somatostatin; used (as its diaspartate salt) for treatment of Cushing's disease. | homodetic cyclic peptide; peptide hormone | antineoplastic agent |
| naluzotan | naluzotan: an antidepressant and anti-anxiety agent; structure in first source | ||
| l 054522 | L 054522: somatostatin receptor subtype 2 agonist; structure in first source | ||
| somatostatin | heterodetic cyclic peptide; peptide hormone |