Video Experimental Relacionado
Updated: May 4, 2026
09:40
Imaging G-protein Coupled Receptor GPCR-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum
Published on: September 20, 2011
17.0K
Adaptación en la salida de la vía de señalización de quimiotaxis
Junhua Yuan1, Richard W Branch, Basarab G Hosu
1Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|April 14, 2012
Resumen
Los motores bacterianos se adaptan a las condiciones cambiantes alterando su composición, específicamente el número de subunidades FliM. Esta remodelación adaptativa optimiza la coincidencia entre la entrada del receptor y la sensibilidad motora, mejorando la función celular.
Área de la Ciencia:
- Quimiotaxis bacteriana y maquinaria molecular.
- La señalización celular y los mecanismos de adaptación.
Sus antecedentes:
- La quimiotaxis bacteriana se basa en grupos de receptores que procesan la entrada y motores flagelares que generan la salida, junto con CheY-P.
- La ultrasensibilidad del motor a las concentraciones de CheY-P presenta un desafío para hacer coincidir la salida del receptor con la entrada del motor.
Objetivo del estudio:
- Para investigar cómo los motores bacterianos optimizan la coincidencia entre la salida del receptor y la entrada del motor.
- Para explorar el mecanismo por el cual el motor cambia su rango de funcionamiento.
Principales métodos:
- Análisis de los componentes de la red de quimiotaxis bacteriana, incluidos los complejos receptores y motores.
- Investigando el papel de las subunidades FliM en el anillo C y su respuesta a los cambios en la concentración de CheY-P.
Principales resultados:
- El motor bacteriano puede cambiar su rango de funcionamiento alterando su composición, específicamente aumentando las subunidades FliM en respuesta a la disminución de CheY-P.
- Este cambio de composición mejora la sensibilidad motora, lo que explica la adaptación en mutantes específicos y la rotación de FliM dependiente de la señal.
Conclusiones:
- La remodelación adaptativa de la composición motora, como el número de subunidad FliM, es un mecanismo clave para optimizar las respuestas celulares.
- Esta estrategia adaptativa es probablemente una característica común en el funcionamiento de diversas máquinas moleculares.
Videos de Conceptos Relacionados
01:21Cell Polarization by Rho Proteins
3.2K
Cell polarity is the asymmetric distribution of cellular and membrane components, making one side of the cell different from the other. This polarity is essential to many processes such as embryogenesis, axon migration, glucose transport across epithelial cells, and directional cell migration. A migrating cell responds to intracellular or extracellular signals via molecular cascades that reorganize the actin cytoskeleton to establish this polarity. In these cells, the Rho family proteins Cdc42,...
3.2K
01:21Chemotaxis and Direction of Cell Migration
5.0K
Cells can detect chemical cues in their environment and reorganize the cytoskeleton to migrate toward them or away from them. This directional migration, called chemotaxis, is essential during embryogenesis and development, immune response, tissue repair and regeneration, and reproduction. These chemical cues can either attract or repel the cell's movement. For example, axon development is determined by a combination of chemoattractants and chemorepellents that direct the growing axon...
5.0K
01:22Diversity in Cell Signaling Responses
7.1K
The physiological function of a cell and cellular communication are outcomes of a range of extrinsic signals, intracellular signaling pathways, and cellular responses. No two cell types express the same repertoire of signaling components. Receptors are highly selective for their cognate ligands, but once activated, they can alter multiple cellular processes such as DNA transcription, protein synthesis, and metabolic activity.
Graded and Abrupt Responses
Some signaling systems generate...
Graded and Abrupt Responses
Some signaling systems generate...
7.1K
01:07Cell Signaling Feedback Loops
5.8K
Positive and negative feedback loops are crucial for regulating biological signaling systems. These feedback loops are processes that connect output signals to their inputs.
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
5.8K
01:27Chemotaxis in E. coli
1.4K
Chemotaxis in Escherichia coli is a sensory-driven motility mechanism that enables bacteria to navigate chemical gradients, moving toward beneficial environments while avoiding harmful conditions. This process relies on a signal transduction system integrating external chemical cues with flagellar motor control.Chemoreceptors and Signal DetectionE. coli detects chemical gradients through methyl-accepting chemotaxis proteins (MCPs), which are membrane-bound chemoreceptors that sense attractants...
1.4K
01:16Transduction
3.0K
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome...
3.0K