Video Experimental Relacionado
Updated: Jun 29, 2026
12:43
Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE
Published on: July 29, 2014
Activación de la vía ERK/MAPK por una isoforma de rap1GAP asociada con G alfa (i)
N Mochizuki1, Y Ohba, E Kiyokawa
1Department of Pathology, Research Institute, International Medical Center of Japan, Tokyo.
Nature
|September 7, 1999
Resumen
La subunidad alfa de la proteína G (i) activa la vía ERK/MAPK mediante el reclutamiento de rap1GAPII. Esto reduce el Rap1 ligado al GTP, activando así la vía mitogénica Ras-ERK/MAPK.
Área de la Ciencia:
- Las vías de señalización celular.
- Biología molecular La biología molecular.
- Receptores acoplados a proteínas G acoplados a proteínas G.
Sus antecedentes:
- La proteína G ((i) heterotrimérica es crucial para la señalización de los receptores de neuropéptidos y hormonas.
- Las subunidades de proteína (alfa y betagamma) activan la cascada ERK/MAPK.
- El constitutivo activo G ((alfa) i2 (gip2) transforma las células y activa ERK/MAPK a través de un mecanismo desconocido.
Objetivo del estudio:
- Aclarar el mecanismo por el cual las subunidades alfa de la proteína G (i) activan la cascada ERK/MAPK.
- Para identificar nuevos reguladores de la vía Ras-ERK/MAPK.
- Para investigar el papel de la proteína II de activación de la GTPasa Rap1 (rap1GAPII) en la señalización G.
Principales métodos:
- Co-inmunoprecipitación para evaluar la unión a las proteínas.
- Pruebas de translocación celular para monitorear la localización de proteínas.
- Los ensayos Rap1 ligados a GTP cuantifican la actividad de Rap1.
- Pruebas de activación de ERK/MAPK.
Principales resultados:
- rap1GAPII se une específicamente a las subunidades alfa de las proteínas G.
- La estimulación de los receptores m2-muscarínicos acoplados a G (i) provoca la translocación de rap1GAPII a la membrana.
- Esta translocación conduce a una disminución de los niveles de Rap1 ligados al GTP.
- La reducción del Rap1 ligado al GTP activa la vía ERK/MAPK.
Conclusiones:
- La subunidad alfa de G ((i) activa la vía mitogénica Ras-ERK/MAPK.
- Esta activación se produce a través del reclutamiento por la membrana de rap1GAPII, que reduce el Rap1 ligado al GTP.
- rap1GAPII actúa como un eslabón crucial entre las subunidades alfa G (i) y la vía Ras-ERK/MAPK.
Videos de Conceptos Relacionados
01:14Rab Proteins
Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
02:38The Ras Gene
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Ras is a superfamily...
01:19Interactions Between Signaling Pathways
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...
01:24Small GTPases - Ras and Rho
Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:
Three regulatory proteins control their activity:
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...
01:22PI3K/mTOR/AKT Signaling Pathway
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 rapamycin-insensitive companion...