Abstract 5154: Regulatory roles of conserved phosphorylation sites in the activation loop of extracellular signal-regulated kinase 1.
Notice bibliographique
Résumé
Abstract The catalytic domains of most eukaryotic protein kinases are highly conserved in their primary structures. Phosphorylation of the activation loop, a variable region between kinase catalytic subdomains VII and VIII, is a common mechanism for regulating protein phosphotransferase activity. Our investigation of the distribution and evolutionary conservation of phosphorylation sites in 492 typical human protein kinase catalytic domains revealed that about 75% of the 303 known activating phosphosites are located within the activation loop. Extracellular signal-regulated kinase 1 (ERK1) belongs to the mitogen-activated protein kinase (MAPK) family, which is one of the most intensively studied protein kinase families and serves as a paradigm for regulation of protein kinases in signaling modules. ERK1 homologues play fundamental roles in regulation of cell growth and proliferation from yeast to humans. In addition to the well-documented TEY activating site in the activation loop of ERK1 and its closest relative ERK2, three flanking phosphosites have been confirmed (T198, T207 and Y210 from ERK1) by high throughput mass spectrometry. We noticed that T207 and Y210 correspond to conserved phosphosites (T/S-XX-Y) located just prior to the subdomain VIII APE motif in many other protein-serine/threonine kinases including CDKs, CAMKs, PKB/Akts and PKCs, which may implicate a common regulatory role for of these phosphosites in a wide range of kinases. To investigate the roles of these three flanking phosphosites, we mutated T198, T207 and Y210 of ERK1 individually and in combinations. In vitro kinase assays with myelin basic protein (MBP) using purified mutants indicated the functional importance of T207 and Y210, but not T198 in regulating ERK1 catalytic activity. By single substitution of the T207 to alanine, the activity of ERK1 towards MBP decreased dramatically without affecting the phosphorylation on TEY motif by MEK1. An additional mutation at Y210 caused the loss of most ERK1 phosphotransferase activity. However, neither of the T207E nor Y210E mutants had the ability to mimic the phosphorylation state and produce the full activation of ERK1. In addition, Y210 could be important for ERK1 to be recognized by MEK1, since the substitution of this residue blocked most of the phosphorylation on TEY sites by this MAPK kinase. Preliminary data also indicated the possibility of autophosphorylation on T207 and Y210, which probably happens after the phosphorylation of the TEY sites by MEK1. The phosphorylation of the flanking sites may help to stabilize the active state of the kinase. Our findings contribute to an improved understanding of MAPK activation and regulation. Hyper-phosphorylation within the kinase activation loop may serve as a general mechanism for protein kinases to achieve full stimulation by autophosphorylation following the initial activation by other upstream kinases. Citation Format: Shenshen Lai, Steven Pelech. Regulatory roles of conserved phosphorylation sites in the activation loop of extracellular signal-regulated kinase 1. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5154. doi:10.1158/1538-7445.AM2013-5154
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,002 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».