Video Experimental Relacionado
Updated: May 4, 2026

10:34
Ligand Nano-cluster Arrays in a Supported Lipid Bilayer
Published on: April 23, 2017
6.4K
Mecanismo molecular de la integración de proteínas de membrana en el retículo endoplasmático
W Mothes1, S U Heinrich, R Graf
1Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Cell
|May 16, 1997
Resumen
Las secuencias transmembranales hidrófobas pueden salir del canal de translocación del retículo endoplasmático hacia la bicapa lipídica antes de que finalice la síntesis de proteínas. Este mecanismo afecta el plegamiento y el ensamblaje de las proteínas de la membrana.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología celular Biología celular.
- La bioquímica es la bioquímica.
Sus antecedentes:
- La integración de proteínas de membrana en el retículo endoplasmático implica complejas vías de translocación.
- Los segmentos hidrófilos e hidrófobos de las cadenas polipeptídicas siguen rutas distintas durante la inserción en la membrana.
Objetivo del estudio:
- Para dilucidar el mecanismo molecular que rige la integración de los segmentos de polipéptido en la membrana del retículo endoplasmático.
- Para entender cómo las secuencias transmembrana hidrofóbicas se liberan en la fase lipídica.
Principales métodos:
- Investigó la síntesis y translocación de proteínas de membrana utilizando un sistema ribosoma-membrana.
- Analizó el comportamiento de los segmentos polipeptídicos durante la integración de proteínas.
Principales resultados:
- Tanto los dominios lumenales como los citosólicos de las proteínas de membrana se sintetizan mientras que el ribosoma está unido a la membrana.
- Las secuencias transmembrana hidrófobas pueden salir lateralmente del canal de translocación hacia el entorno lipídico antes de la terminación de la traducción.
Conclusiones:
- Los hallazgos proporcionan información sobre el proceso dinámico de inserción de proteínas en la membrana.
- Este mecanismo tiene implicaciones significativas para el correcto plegamiento y ensamblaje de las proteínas de la membrana dentro del retículo endoplasmático.
Videos de Conceptos Relacionados
Introduction to Membrane Proteins
65.0K
The cell membrane, or plasma membrane, is an ever-changing landscape. It is described as a fluid mosaic where various macromolecules are embedded in the phospholipid bilayer. Among the macromolecules are proteins. The protein content varies across cell types. For example, mitochondrial inner membranes contain ~76% protein content, while myelin contains ~18% protein content. Individual cells contain many types of membrane proteins—red blood cells contain over 50—and different cell...
65.0K
What are Membranes?
156.6K
A key characteristic of life is the ability to separate the external environment from the internal space. To do this, cells have evolved semi-permeable membranes that regulate the passage of biological molecules. Additionally, the cell membrane defines a cell’s shape and interactions with the external environment. Eukaryotic cell membranes also serve to compartmentalize the internal space into organelles, including the endomembrane structures of the nucleus, endoplasmic reticulum and...
156.6K
What are Membranes?
14.5K
A cell's plasma membrane demarcates the cell's borders and determines the nature of its interaction with the environment. Cells exclude certain substances, take in others, and excrete some others in controlled quantities. The plasma membrane must be flexible to allow certain cells, such as red and white blood cells, to change their shape while passing through narrow capillaries. These are the more obvious plasma membrane functions. In addition, the plasma membrane's surface carries...
14.5K
Mechanisms of Membrane Domain Formation
3.2K
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.2K
Integrins
4.8K
Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
4.8K
Activation of Integrins
4.3K
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
4.3K

