Related Experiment Video

Updated: Jul 14, 2026

In situ Subcellular Fractionation of Adherent and Non-adherent Mammalian Cells
09:20

In situ Subcellular Fractionation of Adherent and Non-adherent Mammalian Cells

Published on: July 23, 2010

Papillomavirus binding factor (PBF)-mediated inhibition of cell growth is regulated by 14-3-3beta

Nadine Sichtig1, Steffi Silling, Gertrud Steger

  • 1Institute of Virology, University of Cologne, Fürst-Pückler-Strasse 56, 50935 Cologne, Germany.

Archives of Biochemistry and Biophysics
|May 29, 2007
PubMed

Insights

Papillomavirus (PV)-binding factor (PBF) interacts with 14-3-3beta, influencing cell growth. This interaction is regulated by PI3K/Akt signaling, revealing PBF

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Papillomavirus (PV)-binding factor (PBF), also known as Huntington's disease binding protein 2 (HDBP2), is a novel nuclear-shuttling transcription factor.
  • Its precise function and regulatory mechanisms remain largely uncharacterized.

Purpose of the Study:

  • To elucidate the function and regulation of PBF.
  • To identify PBF interaction partners and understand their role in cellular processes.

Main Methods:

  • Yeast two-hybrid screening to identify PBF interacting proteins.
  • Co-immunoprecipitation assays to confirm PBF-14-3-3beta interaction.
  • Kinase assays to investigate phosphorylation of PBF motifs.
  • Cellular localization studies and cell growth assays.

Main Results:

  • Identified 14-3-3beta as a PBF interaction partner, binding through specific motifs.
  • Demonstrated that PI3K/Akt signaling pathway kinases phosphorylate these motifs, facilitating PBF-14-3-3beta association.
  • Observed that PBF regulates cell growth, with overexpression inhibiting growth, an effect enhanced by a 14-3-3 binding-deficient mutant.

Conclusions:

  • Characterized PBF as a novel cellular factor involved in mediating the effects of PI3K/Akt signaling and 14-3-3 proteins on cell growth.
  • The PBF-14-3-3beta interaction plays a role in regulating PBF's subcellular localization and cellular function.

More Related Videos

Analysis of Cell Cycle Position in Mammalian Cells12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry09:38

Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry

Published on: June 26, 2019

Related Concept Videos

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.
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...
Molecular Factors Affecting Cell Division01:27

Molecular Factors Affecting Cell Division

Several external and internal factors influence the initiation and inhibition of cell division. For instance, the death of nearby cells or the release of human growth hormone (hGH) promotes cell division. In contrast, lack of hGH or crowding of cells can inhibit cell division.
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
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...
Inhibitors of Virion Maturation and Assembly01:19

Inhibitors of Virion Maturation and Assembly

As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

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.