Video Experimental Relacionado
Updated: May 2, 2026
11:54
Detection of Protein Ubiquitination Sites by Peptide Enrichment and Mass Spectrometry
Published on: March 23, 2020
9.4K
La proteómica cuantitativa revela la función de las cadenas de ubiquitina no convencionales en la degradación
Ping Xu1, Duc M Duong, Nicholas T Seyfried
1Department of Human Genetics, Center for Neurodegenerative Diseases, Emory University, Atlanta, GA 30322, USA.
Cell
|April 7, 2009
Resumen
Las cadenas de poliubiquitina no convencionales, más allá de los enlaces K48 y K63, son vitales para la degradación de las proteínas y la función celular. Estas cadenas no K63, incluidos los enlaces K11, juegan un papel crítico en vías como la degradación asociada al retículo endoplasmático (ERAD).
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Biología celular Biología celular.
Sus antecedentes:
- La modificación de la ubiquitina regula la función y la degradación de las proteínas.
- Las cadenas de poliubiquitina señalan la degradación proteasomal (K48) o las funciones no proteolíticas (K63).
- Las funciones de otros enlaces de poliubiquitina (K6, K11, K27, K29, K33) permanecen en gran parte sin caracterizar.
Objetivo del estudio:
- Investigar la abundancia in vivo y las funciones de las cadenas no convencionales de poliubiquitina.
- Para identificar sustratos y vías reguladas por enlaces de ubiquitina no K63.
- Para aclarar el papel específico de las cadenas de poliubiquitina ligadas a K11 en los procesos celulares.
Principales métodos:
- Proteómica basada en la espectrometría de masas cuantitativa para perfilar el proteoma de la levadura y las proteínas ubiquitinadas.
- Comparación de cepas de levadura mutantes de tipo silvestre y ubiquitina K11R.
- Identificación de los sustratos específicos del enlace K11.
Principales resultados:
- Los enlaces de poliubiquitina no K63 son abundantes in vivo y pueden dirigirse a las proteínas para su degradación.
- La ubiquitina ligada a K48 por sí sola es insuficiente para la viabilidad de la levadura, lo que indica funciones parcialmente redundantes de diferentes enlaces.
- Las cadenas ligadas a K11 se dirigen específicamente a Ubc6, una enzima clave en la degradación asociada al retículo endoplasmático (ERAD).
Conclusiones:
- Las cadenas de poliubiquitina no convencionales son críticas para el sistema ubiquitina-proteasoma.
- Las cadenas de poliubiquitina vinculadas a K11 juegan un papel importante en la vía ERAD.
- Comprender los diversos vínculos de la ubiquitina es esencial para comprender la homeostasis de las proteínas y la regulación celular.
Videos de Conceptos Relacionados
02:04Covalently Linked Protein Regulators
8.2K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
8.2K
02:18The Proteasome
7.8K
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
7.8K
02:58Regulated Protein Degradation
6.6K
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
6.6K
02:11Proteins: From Genes to Degradation
11.9K
Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick. Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation.
Transcription is the synthesis of RNA...
Transcription is the synthesis of RNA...
11.9K
01:13The Proteasome
1.6K
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
1.6K
01:17The Proteasome Structure
2.2K
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...
2.2K