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Lipid signaling:
Ceramide
- Sphingomyelinase (SMase) or sphingomyelin phosphodiesterase is a hydrolase involved in sphingolipid metabolism. It catalyzes the breakdown of sphingomyelin (SM) to phosphocholine and ceramide[1].
- Acid-beta-glucosidase or glucosylceramidase is a lysozomal enzyme (EC number 3.2.1.45), which cleaves glucosylceramide to glucose and ceramide. It catalyzes hydrolysis of the sphingolipid, , to at the acidic pH prevailing within the lysosome. .
- The molecular function of galactosylceramidase is hydrolysis of a O-glycosyl bond to remove galactose from ceramide and other sphingolipids.
Sphingosine-1-Phosphate
Glucosylceramide
Phosphatidylinositol bisphosphate (PIP2)
Phosphatidylinositol 4,5-bisphosphate (PIP2) binds to and directly activates inwardly rectifying potassium channels. Inward rectifier KCh.
Prostaglandins
Endocannabinoids
Retinol derivatives
Retinal
Retinoic acid
Steroid Hormones and their receptors
This large and diverse class of steroids are biosynthesized from isoprenoids and structurally resemble cholesterol. Mammalian steroid hormones can be grouped into five groups by the receptors to which they bind: glucocorticoids, mineralocorticoids, androgens, estrogens, and progestogens. Vitamin D derivatives are a sixth closely related hormone system with homologous receptors. They have some of the characteristics of true steroids as receptor ligands. For example, is an important estrogen steroid hormone in both women and men. It is a typical steroid with core four-ring system (ABCD), composed of 17 carbon atoms.
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes.
and its derivatives have some mineralocorticoid action in addition to the glucocorticoid effect.
(hydrocortisone) is a corticosteroid with both glucocorticoid and mineralocorticoid activity and effects.
Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor. is a glucocorticoid medication. It is the most potent glucocorticoid and it has not mineralocorticoid potency.
- Glucocorticoid receptor. (1m2z).
- Forkhead box proteins (FOX) are transcription factors involved in regulation of gene expression.[3]. FOXO1 activation contributes to glucocorticoid-induced beta cell death[4]. FOX contain a DNA-binding motif (DBD) of 80-100 amino acids having a winged-helix shape.
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- . Water molecules shown as red spheres.
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- Nuclear receptor coactivator (NCOA) is a protein recruited by nuclear receptors in order to enhance or repress DNA transcription. NCOA is involved in coactivation with transcription factors[5]. NCOA1 shows histone acetyltransferase activity and is required for steroid hormone response. NCOA2 is a DNA transcription coactivator with glucocorticoid receptor.
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- . Water molecules are shown as red spheres.
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- Thioredoxin Reductase (TrxR) is an enzyme which reduces thioredoxin using NADPH[6]. Mutations in TrxR-2 are associated with familial glucocorticoid deficiency[7]. Thioredoxin Reductase (TrxR) is an enzyme which reduces thioredoxin using NADPH[8]. TrxR-2 is mitochondrial. For more details see User:Sarah Abdalla/Thioredoxin Reductase. TrxR and Trx form an [9]. . Water molecules are shown as red spheres.
- Microsomal Prostaglandin E synthase (PGES) converts cyclooxygenase (COX)-derived prostaglandin to PGE2. It is membrane-associated and belongs to the microsomal glutathione S-transferase family. PGES is preferentially linked with the inducible COX-2[10] . PGES is induced by proinflammatory stimuli and down-regulated by anti-inflammatory glucocorticoids[11]. Microsomal Prostaglandin E synthase (coordinates are from OPM database. The [12]. Water molecules are shown as red spheres.
Mineralocorticoids are a class of corticosteroids. Mineralocorticoids are produced in the adrenal cortex and influence salt and water balances (electrolyte balance and fluid balance). The primary mineralocorticoid is .
- Mineralocorticoid receptor (MR) in epithelial cells is activated by the mineralocorticoid hormone aldosterone promoting renal sodium retention and potassium excretion. It is nuclear receptor. In non epithelial cells MR is activated by cortisol[13]. MR is exposed to many steroids including cortisol, cortisone and progesterone, however, aldosterone and deoxycorticosterone are its physiological ligands. MR mutations are the principal cause of renal pseudohypoaldosteronism[14]. MR mutation S810L causes early-onset hypertension[15]. Inhibition of cardia MR prevents doxorubicin-induced cardiotoxicity[16]. MR is an important proadipogenic transcription factor that may mediate aldosterone and glucocorticoid effects on adipose tissue development and hence on obesity and development of metabolic syndrome[17]. The MR ligand aldosterone binds in a (Alpha Helices, Beta Strands , Loops ,Turns). [18]. . Water molecules are shown as red spheres.
Signaling Pathways:
ABA Signaling Pathway
Protein Kinases:
Tyrosine kinase
- Receptor tyrosine kinases
- Tyrosine kinase
- Janus kinase or tyrosine-protein kinase JAK (JAK) are nonreceptor tyrosine kinases which transduces cytokine-mediated signals via the JAK-STAT pathway. The JAK-STAT pathway transmits signals through the cell membrane to DNA promoters thus causing transcription.
Protein kinase C
MAPK
CAMP-dependent protein kinase
Chemotaxis:
Mechanotransduction:
Thermoception
Transient receptor potential channels
Voltage-gated channels
Visual phototransduction
Light is detected by rhodopsin in rod and cone cells.
Photoreceptor pigments
Circadian clock
Protein phosphatases:
Second messengers
cAMP is second messenger
CAMP-dependent protein kinase
IP3 is second messenger
Receptors that activate this pathway (Phospholipase C) are mainly G protein-coupled receptors coupled to the Gαq subunit, including:
- 5-HT2 serotonergic receptors (5-hydroxytryptamine receptor#Structural highlights/Specific Function of 5-HT2B).
- α1 adrenergic receptors
- Calcitonin receptors
- Histamine H1 receptor. The H1 receptor is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled receptors. The H1 receptor is linked to an intracellular G-protein (Gq) that activates phospholipase C and the inositol triphosphate signaling pathway. When a ligand binds to a G protein-coupled receptor that is coupled to a Gq heterotrimeric G protein, the α-subunit of Gq can bind to and induce activity in the PLC isozyme PLC-β, which results in the cleavage of PIP2 into IP3 and DAG.
- Metabotropic glutamate receptor 1 and metabotropic glutamate receptor 5 belong to group I and activate phospholipase C. For details see Metabotropic glutamate receptor 5.
- M1, M3, and M5 muscarinic receptors. Muscarinic acetylcholine receptors (mAChR) contain 5 subtypes M1-M5. Subtypes M1, M3, M5 activate phospholipase C which leads to activation of protein kinase C.
- Inositol 1,4,5-Trisphosphate Receptor
Paracrine signaling: fibroblast growth factor (FGF) family, Hedgehog family, Wnt family, and TGF-β superfamily
Fibroblast growth factor and Fibroblast growth factor receptor (FGFR). FGFR belongs to Receptor tyrosine kinases, class V.
Sonic Hedgehog
Ca2+ signalling processes
H+/K+-ATPase signal pathway (acetylcholine, histamine, and gastrin) activates the pump in order to move the vesicles toward the lumen.
Proton pump
Signal transducing adaptor proteins (STAPs)
GTPase
The Mitogen-activated protein kinase cascade
MAPKs are involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflammatory cytokines. They regulate cell functions including proliferation, gene expression, differentiation, mitosis, cell survival, and apoptosis.
Inflammatory response
Allostery
ATPase
