Related Experiment Video

Updated: Jul 3, 2026

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus
09:53

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Published on: August 25, 2017

Skp2 inversely correlates with p27 and tuberin in transformed cells

M Rosner1, M Hanneder, N Siegel

  • 1Medical Genetics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.

Amino Acids
|July 8, 2008
PubMed

Insights

The skp2 protein, crucial for cell cycle progression, is found in both the cytoplasm and nucleus. Its levels inversely correlate with p27Kip1 (p27) and tuberin, offering new insights into cell cycle control.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • p27Kip1 (p27) regulates mammalian cell cycle progression by controlling entry into S phase.
  • p27 degradation by skp2-containing E3 ubiquitin ligase targets it for proteasomal degradation.
  • Tuberin binds p27, protecting it from skp2-mediated degradation.

Purpose of the Study:

  • To investigate the subcellular localization of skp2.
  • To explore the relationship between skp2, p27, and tuberin levels in cell cycle control.

Main Methods:

  • Immunoblotting to detect endogenous protein levels.
  • Cellular fractionation to determine subcellular localization.

Main Results:

  • skp2 is localized in both the cytoplasm and nucleus.
  • An inverse correlation was observed between endogenous skp2 levels and p27/tuberin levels in transformed cells.
  • This inverse correlation was also noted under various growth conditions.

Conclusions:

  • skp2's dual localization provides a more complete understanding of its role in cell cycle regulation.
  • The inverse correlation suggests a dynamic interplay between skp2, p27, and tuberin in controlling cell cycle progression.

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...
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...
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.
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
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...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...