Video Experimental Relacionado
Updated: Jul 6, 2026
15:43
Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
Published on: January 7, 2013
La activación de la proteína quinasa C disminuye la fosforilación de c-Jun en sitios que regulan negativamente su
W J Boyle1, T Smeal, L H Defize
1Molecular Biology and Virology Laboratory, Salk Institute, La Jolla, California 92037.
Cell
|February 8, 1991
Resumen
En las células en reposo, la proteína c-Jun está inactiva debido a la fosforilación. La activación de la proteína quinasa C desencadena la desfosforilación, mejorando la actividad de unión de AP-1 y c-Jun.
Área de la Ciencia:
- Biología molecular La biología molecular.
- La señalización celular de las células.
Sus antecedentes:
- c-Jun es un factor de transcripción que regula la expresión génica.
- La fosforilación de c-Jun afecta sus actividades de unión al ADN y trans-activación.
Objetivo del estudio:
- Investigar el papel de la fosforilación c-Jun en la regulación de su actividad.
- Para identificar sitios específicos de fosforilación y su impacto en la unión al ADN.
Principales métodos:
- Ensayos de fosforilación in vitro con el uso de la glicogénica sintetasa quinasa 3 (GSK-3).
- Mutagénesis dirigida al sitio de los sitios de fosforilación c-Jun.
- Análisis de la actividad de unión de AP-1 después de la activación de la proteína quinasa C.
Principales resultados:
- Fosforilatos GSK-3 c-junio en tres sitios específicos (residuos 227-252).
- La activación de la proteína quinasa C causa la desfosforilación de c-Jun, aumentando la unión a AP-1.
- La mutación de la serina 243 a fenilalanina mejora la trans-activación de c-Jun en 10 veces.
Conclusiones:
- c-Jun existe en un estado latente, fosforilado en las células en reposo.
- La desfosforilación específica del sitio, desencadenada por la proteína quinasa C, activa c-Jun.
- El estado de fosforilación es un regulador clave de la función transcripcional de c-Jun.
Videos de Conceptos Relacionados
02:54Protein Kinases and Phosphatases
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
02:34Inhibition of Cdk Activity
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
01:22Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
01:07MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
01:20The JAK-STAT Signaling Pathway
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
02:34Inhibition of CDK Activity
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...