Related Experiment Video
Updated: Jul 21, 2026
12:19
Analysis of Cell Cycle Position in Mammalian Cells
Published on: January 21, 2012
E2F4 and E2F5 play an essential role in pocket protein-mediated G1 control
S Gaubatz1, G J Lindeman, S Ishida
1The Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115, USA.
Molecular Cell
|October 13, 2000
Summary
Simultaneous inactivation of E2F4 and E2F5 transcription factors in mice causes neonatal lethality, indicating overlapping developmental roles. These factors are crucial for G1 cell cycle arrest but not for general proliferation.
Area of Science:
- Molecular Biology
- Developmental Biology
- Cell Cycle Regulation
Background:
- E2F transcription factors regulate cell proliferation.
- The E2F family has diverse members with potentially distinct functions.
- Individual roles of E2F4 and E2F5 in cell cycle control remain poorly understood.
Purpose of the Study:
- To investigate the individual and overlapping functions of E2F4 and E2F5.
- To determine the role of E2F4 and E2F5 in mouse development and cell cycle regulation.
Main Methods:
- Generation of mice with simultaneous inactivation of E2F4 and E2F5.
- Analysis of embryonic fibroblast proliferation and cell cycle kinetics.
- Assessment of G1 arrest in response to p16INK4a.
Main Results:
- Simultaneous E2F4 and E2F5 inactivation leads to neonatal lethality in mice.
- Embryonic fibroblasts lacking E2F4 and E2F5 proliferate normally and reenter G0 with normal kinetics.
- These cells fail to arrest in the G1 phase in response to p16INK4a.
Conclusions:
- E2F4 and E2F5 have overlapping functions essential for mouse development.
- E2F4 and E2F5 are dispensable for cell cycle progression.
- E2F4 and E2F5 are required for pocket protein-mediated G1 arrest in cycling cells.
Related Concept Videos
01:23Negative 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.
02:11The Cell Cycle Control System
The cell cycle is an organized set of events that leads the cell to divide into two daughter cells, each containing chromosomes identical to the parent cell. It is the cell cycle that leads to the formation of an entire organism from a single-cell zygote. Besides, cell division also functions in the renewal or repair of tissues in adult multicellular eukaryotes. For example, in the bone marrow, the stem cells divide to form new blood cells. Although essential for several functions, cell...
02:38Mitogens and the Cell Cycle
Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
02:11The Cell Cycle Control System
The cell cycle is an organized set of events that leads the cell to divide into two daughter cells, each containing chromosomes identical to the parent cell. It is the cell cycle that leads to the formation of an entire organism from a single-cell zygote. Besides, cell division also functions in the renewal or repair of tissues in adult multicellular eukaryotes. For example, in the bone marrow, the stem cells divide to form new blood cells. Although essential for several functions, cell...
02:38Mitogens and the Cell Cycle
Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
01:28The Cell Cycle Control System
The cell cycle regulation directs how a cell proceeds from one phase to the next and begins mitosis. The cell cycle control system includes intracellular regulatory molecules and external triggers. They provide "stop" or "advance" signals and operate at specific cell cycle stages termed checkpoints to ensure that a particular process is completed before the cell advances to the next phase.
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and function at the cell...
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and function at the cell...