Target type: biologicalprocess
Any process that stops, prevents, or reduces the frequency, rate or extent of the introduction of a phosphate group to a tyrosine residue of a STAT (Signal Transducer and Activator of Transcription) protein. [GOC:jl, PMID:11426647]
Negative regulation of tyrosine phosphorylation of STAT proteins is a crucial process that controls the activity of signal transducer and activator of transcription (STAT) proteins, which are key mediators of cytokine and growth factor signaling pathways. Tyrosine phosphorylation of STAT proteins is essential for their activation, allowing them to translocate to the nucleus and regulate gene expression. However, uncontrolled STAT activation can lead to various diseases, including cancer and autoimmune disorders. Therefore, negative regulation mechanisms are critical for maintaining proper STAT signaling and preventing aberrant cell growth.
There are several mechanisms involved in the negative regulation of STAT tyrosine phosphorylation. These include:
1. **Protein tyrosine phosphatases (PTPs):** PTPs are enzymes that specifically remove phosphate groups from tyrosine residues. Several PTPs, such as SHP-1 and SHP-2, have been shown to dephosphorylate and inactivate STAT proteins, thereby inhibiting their signaling.
2. **Ubiquitination and proteasomal degradation:** STAT proteins can be targeted for ubiquitination, a process that marks them for degradation by the proteasome. This degradation pathway serves to reduce STAT protein levels and limit their activity.
3. **Suppression of upstream signaling pathways:** Negative regulators can act upstream of STAT proteins by inhibiting the kinases that phosphorylate them. For example, the protein SOCS (suppressor of cytokine signaling) family members bind to activated cytokine receptors and prevent further STAT activation.
4. **Direct interactions with STAT proteins:** Some proteins directly bind to STAT proteins and inhibit their activity. For example, the protein PIAS (protein inhibitor of activated STAT) can block STAT dimerization and nuclear translocation.
5. **MicroRNAs:** MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Certain miRNAs have been shown to target STAT mRNAs and reduce their translation, thereby inhibiting STAT protein production.
These negative regulatory mechanisms ensure that STAT signaling is tightly controlled and that appropriate cellular responses are elicited in response to external stimuli. Dysregulation of these processes can contribute to the development of various diseases, highlighting their importance in maintaining cellular homeostasis.'
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Protein | Definition | Taxonomy |
---|---|---|
Protein mono-ADP-ribosyltransferase PARP14 | A protein mono-ADP-ribosyltransferase PARP14 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q460N5] | Homo sapiens (human) |
Tyrosine-protein phosphatase non-receptor type 2 | A tyrosine-protein phosphatase non-receptor type 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P17706] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
---|---|---|---|
5-iodo-2-(oxaloamino)benzoic acid | organoiodine compound | ||
pj-34 | PJ34 : A member of the class of phenanthridines that is 5,6-dihydrophenanthridine substituted at positions 2 and 6 by (N,N-dimethylglycyl)amino and oxo groups, respectively. It is a potent inhibitor of poly(ADP-ribose) polymerases PARP1 and PARP2 (IC50 of 110 nM and 86 nM, respectively) and exhibits anti-cancer, cardioprotective and neuroprotective properties. | phenanthridines; secondary carboxamide; tertiary amino compound | angiogenesis inhibitor; anti-inflammatory agent; antiatherosclerotic agent; antineoplastic agent; apoptosis inducer; cardioprotective agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; neuroprotective agent |
lithocholic acid | lithocholate : A bile acid anion that is the conjugate base of lithocholic acid. lithocholic acid : A monohydroxy-5beta-cholanic acid with a alpha-hydroxy substituent at position 3. It is a bile acid obtained from chenodeoxycholic acid by bacterial action. Lithocholic Acid: A bile acid formed from chenodeoxycholate by bacterial action, usually conjugated with glycine or taurine. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as cholagogue and choleretic. | bile acid; C24-steroid; monohydroxy-5beta-cholanic acid | geroprotector; human metabolite; mouse metabolite |
glycyrrhetinic acid | cyclic terpene ketone; hydroxy monocarboxylic acid; pentacyclic triterpenoid | immunomodulator; plant metabolite | |
oleanolic acid | hydroxy monocarboxylic acid; pentacyclic triterpenoid | plant metabolite | |
vanadates | vanadate(3-) : A vanadium oxoanion that is a trianion with formula VO4 in which the vanadium is in the +5 oxidation state and is attached to four oxygen atoms. Vanadates: Oxyvanadium ions in various states of oxidation. They act primarily as ion transport inhibitors due to their inhibition of Na(+)-, K(+)-, and Ca(+)-ATPase transport systems. They also have insulin-like action, positive inotropic action on cardiac ventricular muscle, and other metabolic effects. | trivalent inorganic anion; vanadium oxoanion | EC 3.1.3.1 (alkaline phosphatase) inhibitor; EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor; EC 3.1.3.41 (4-nitrophenylphosphatase) inhibitor; EC 3.1.3.48 (protein-tyrosine-phosphatase) inhibitor |
ursolic acid | hydroxy monocarboxylic acid; pentacyclic triterpenoid | geroprotector; plant metabolite | |
madecassic acid | monocarboxylic acid; pentacyclic triterpenoid; tetrol | antioxidant; plant metabolite | |
maslinic acid | (2Alpha,3beta)-2,3-dihydroxyolean-12-en-28-oic acid: from Luehea divaricata and Agrimonia eupatoria | dihydroxy monocarboxylic acid; pentacyclic triterpenoid | anti-inflammatory agent; antineoplastic agent; antioxidant; plant metabolite |
4-Methoxybenzamide | benzamides | ||
geniposide | terpene glycoside | ||
asiatic acid | monocarboxylic acid; pentacyclic triterpenoid; triol | angiogenesis modulating agent; metabolite | |
celastrol | monocarboxylic acid; pentacyclic triterpenoid | anti-inflammatory drug; antineoplastic agent; antioxidant; EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor; Hsp90 inhibitor; metabolite | |
cryptotanshinone | cryptotanshinone: from Salvia miltiorrhiza | abietane diterpenoid | anticoronaviral agent |
boswellic acid | boswellic acid: ursane type; RN given refers to (3alpha,4beta)-isomer; active principle of salai guggal; see also record for salai guggal | triterpenoid | |
procurcumenol | procurcumenol: RN given for (1S-(1alpha,3abeta,8aalpha))-isomer; epiprocurcumenol is the (1S-(1alpha,3aalpha,8aalpha))-isomer; a TNF-alpha antagonist isolated from Curcuma zedoaria; structure in first source | sesquiterpenoid | |
pinocembrin | |||
genipin | iridoid monoterpenoid | anti-inflammatory agent; antioxidant; apoptosis inhibitor; cross-linking reagent; hepatotoxic agent; uncoupling protein inhibitor | |
2-(oxaloamino)benzoic acid | (oxaloamino)benzoic acid | ||
chlorogenic acid | caffeoylquinic acid: Antiviral Agent; structure in first source chlorogenate : A monocarboxylic acid anion that is the conjugate base of chlorogenic acid; major species at pH 7.3. | cinnamate ester; tannin | food component; plant metabolite |
tocopherylquinone | tocopherylquinone: RN refers to (3R-(3R*,7R*,11R*))-isomer; structure | ||
illudalic acid | illudalic acid: isolated from Clitocybe illudens; structure in first source | ||
eupatoriopicrine | germacranolide | ||
2-amino-6-chloropurine | 6-chloroguanine : An organochlorine compound that is 7H-purin-2-amine substituted by a chloro group at position 6. 6-chloroguanine: an antimalarial that inhibits hypoxanthine-guanine-xanthine phosphoribosyltransferase; structure in first source | 2-aminopurines; organochlorine compound | |
corosolic acid | triterpenoid | metabolite | |
11-keto-boswellic acid | |||
rucaparib | AG14447: Poly(ADP-ribose) polymerase inhibitor; structure in first source | azepinoindole; caprolactams; organofluorine compound; secondary amino compound | antineoplastic agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
3-epioleanolic acid | triterpenoid | metabolite | |
veliparib | benzimidazoles | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
oleanonic acid | oleanonic acid: structure in first source | ||
zedoarondiol | zedoarondiol: structure in first source | ||
niraparib | niraparib : A 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide that has S-configuration. It is a potent inhibitor of PARP1 and PARP2 (IC50 of 3.8 and 2.1 nM, respectively) and approved as a first-line maintenance treatment for women with advanced ovarian cancer after responding to platinum-based chemotherapy. niraparib: structure in first source | 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide | antineoplastic agent; apoptosis inducer; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; radiosensitizing agent |
formylchromone | formylchromone: structure in first source | ||
rk 682 | |||
variabilin | variabilin: an RGD-containing antagonist of glycoprotein IIb-IIIa from the hard tick, Dermacentor variabilis; amino acid sequence given in first source | ||
xav939 | XAV939 : A thiopyranopyrimidine in which a 7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine skeleton is substituted at C-4 by a hydroxy group and at C-2 by a para-(trifluoromethyl)phenyl group. XAV939: selectively inhibits beta-catenin-mediated transcription; structure in first source | (trifluoromethyl)benzenes; thiopyranopyrimidine | tankyrase inhibitor |
bmn 673 | talazoparib: inhibits both PARP1 and PARP2; structure in first source |