Related Experiment Video

Updated: Aug 11, 2026

Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics
06:00

Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics

Published on: May 14, 2016

p205, a potential tumor suppressor, inhibits cell proliferation via multiple pathways of cell cycle regulation

Benyam Asefa1, Jonathan M Dermott, Philipp Kaldis

  • 1Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute-Frederick, Building 560, Room 31-56, Frederick, MD 21702-1201, USA.

FEBS Letters
|February 7, 2006
PubMed

Insights

p205 protein inhibits cell growth by interacting with cell cycle regulators like p53 and Rb. It also independently delays cell cycle progression, revealing a complex mechanism for cell growth arrest.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Cancer Research

Background:

  • p205 is an interferon-inducible protein belonging to the p200 family.
  • p205 regulates cell proliferation, with overexpression inhibiting cell growth.
  • The precise mechanism of p205-mediated growth inhibition is not fully understood.

Purpose of the Study:

  • To investigate the effect of p205 on p53 and Rb-dependent cell cycle regulation pathways.
  • To elucidate the molecular mechanisms underlying p205-induced growth inhibition.

Main Methods:

  • Assessed p205 expression and its impact on cell cycle regulators.
  • Performed in vitro p21 promoter activation assays.
  • Utilized yeast two-hybrid screening to identify binding partners.
  • Investigated p205 interaction with p53, Rb, and Cdk2 kinase activity.

Main Results:

  • p205 expression elevates p21 levels and activates the p21 promoter in a p53-dependent manner.
  • p205 increases Rb expression and directly binds to both Rb and p53.
  • p205 induces p53/Rb-independent growth inhibition by delaying G2/M phase progression.
  • p205 is a substrate for Cdk2 kinase and interacts with HoxB2.

Conclusions:

  • p205 induces cell growth arrest through interactions with multiple cell cycle regulatory factors.
  • The growth inhibitory effects of p205 involve both p53/Rb-dependent and independent pathways.
  • p205 represents a novel target for understanding and potentially manipulating cell cycle control.

More Related Videos

Yeast As a Chassis for Developing Functional Assays to Study Human P5314:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

Related Concept Videos

Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Negative Regulator Molecules01:23

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.
Inhibition of Cdk Activity02:34

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...
Inhibition of CDK Activity02:34

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...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...