Video Experimental Relacionado

Updated: Jul 7, 2026

Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols

Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols

Published on: June 6, 2017

Asociación de la ciclina E humana con una proteína quinasa en fase G1-S periódica

V Dulić¹, E Lees, S I Reed

¹Department of Molecular Biology, Scripps Research Institute, La Jolla, CA 92037.

Science (New York, N.Y.)

|September 25, 1992

Resumen

La proteína ciclina E humana y su actividad quinasa son cruciales para la transición de la fase G1 a la fase S en el ciclo celular. El complejo ciclina E-Cdk2 actúa como un regulador clave, con niveles que alcanzan su punto máximo durante las últimas fases G1 y S temprano.

Área de la Ciencia:

Biología celular Biología celular.
Biología Molecular Biología Molecular
La bioquímica es la bioquímica.

Sus antecedentes:

Las ciclinas G1 regulan la transición de fase G1 a S en Saccharomyces cerevisiae.
La ciclina E se identificó a través de una pantalla para cDNA humanos que complementan la levadura en ciernes con deficiencia de ciclina G1.

Objetivo del estudio:

Investigar el papel de la ciclina E humana en la regulación del ciclo celular.
Para caracterizar la actividad y la asociación del ciclo celular de la ciclina E y su quinasa.

Principales métodos:

Cribado funcional de ADNc humano en levaduras.
Análisis de los niveles de proteína ciclina E y la actividad de la quinasa asociada a lo largo del ciclo celular humano.
Identificación de los complejos ciclina E-Cdk2.

Principales resultados:

La ciclina humana E rescata la deficiencia de ciclina G1 en las levaduras.
La proteína ciclina E y la actividad de la quinasa asociada exhiben fluctuaciones periódicas durante el ciclo celular.
Los niveles máximos de la ciclina E y la actividad de la quinasa ocurren al final de la fase G1 y al principio de la fase S.
La ciclina E forma complejos con Cdk2, mostrando actividad de la quinasa asociada.

Conclusiones:

El complejo ciclina E-Cdk2 es una proteína quinasa reguladora específica de la fase G1-S humana.
La ciclina E juega un papel conservado en la progresión del ciclo celular de la fase G1 a la fase S.

Más Videos Relacionados

Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis

Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis

Published on: December 5, 2017

Visualizing Single-Stranded DNA Foci in the G1 Phase of the Cell Cycle

Visualizing Single-Stranded DNA Foci in the G1 Phase of the Cell Cycle

Published on: December 22, 2023

Videos de Conceptos Relacionados

Negative Regulator Molecules

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.

GTPases and their Regulation

GTPases and their Regulation

Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...

Positive Regulator Molecules

Positive Regulator Molecules

Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.

Inhibition of Cdk Activity

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...

GTPases and their Regulation

GTPases and their Regulation

Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...

Activation and Inactivation of G Proteins

Activation and Inactivation of G Proteins

Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...