Video Experimental Relacionado
Updated: Sep 27, 2025
07:49
Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods
Published on: July 17, 2019
6.2K
Desbloqueando los secretos de la activación de la Janus quinasa
Ross L Levine1, Stevan R Hubbard2
1Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Science (New York, N.Y.)
|April 7, 2022
Resumen
Se determinó la estructura completa de Janus kinase (JAK), lo que ofrece nuevas ideas para el desarrollo de fármacos dirigidos. Esta información estructural es crucial para diseñar terapias más efectivas con inhibidores de JAK.
Área de la Ciencia:
- La bioquímica
- Biología estructural
- Farmacología
Sus antecedentes:
- Las Janus kinases (JAK) son enzimas de señalización intracelular críticas involucradas en las vías de señalización de citoquinas.
- La desregulación de la señalización JAK está implicada en varias enfermedades autoinmunes, afecciones inflamatorias y cánceres.
- La orientación de los JAK con inhibidores de moléculas pequeñas ha surgido como una estrategia terapéutica significativa.
Objetivo del estudio:
- Para determinar la estructura de longitud completa de una cinasa Janus específica.
- Proporcionar una base estructural detallada para comprender la activación e inhibición de JAK.
- Facilitar el diseño de fármacos basados en la estructura para nuevos inhibidores de JAK.
Principales métodos:
- Se empleó la cristalografía de rayos X para resolver la estructura tridimensional.
- Se utilizaron ensayos bioquímicos para caracterizar la actividad de la quinasa y la unión al inhibidor.
- Se utilizó el modelado computacional para analizar las características e interacciones estructurales.
Principales resultados:
- Se aclaró la estructura completa de la cinasa de Janus de longitud completa, revelando los estados conformacionales clave.
- El análisis estructural identificó regiones específicas cruciales para la actividad de la quinasa y la interacción con el sustrato.
- Se visualizaron los modos de unión de inhibidores conocidos, destacando el potencial para mejorar el diseño de fármacos.
Conclusiones:
- La estructura de Janus quinasa de longitud completa determinada proporciona detalles sin precedentes a nivel atómico para el desarrollo de fármacos.
- Esta visión estructural permite el diseño racional de inhibidores JAK más selectivos y potentes.
- Los hallazgos allanan el camino para mejorar las estrategias terapéuticas dirigidas a las enfermedades mediadas por JAK.
Videos de Conceptos Relacionados
01:20The JAK-STAT Signaling Pathway
9.4K
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...
9.4K
01:07MAPK Signaling Cascades
6.3K
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...
6.3K
01:25cAMP-dependent Protein Kinase Pathways
6.7K
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
6.7K
01:22Amplifying Signals via Enzymatic Cascade
11.0K
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...
11.0K
01:19Interactions Between Signaling Pathways
6.6K
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
6.6K
01:22PI3K/mTOR/AKT Signaling Pathway
4.1K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
4.1K