Related Experiment Video

Updated: May 1, 2026

Assays for the Degradation of Misfolded Proteins in Cells
10:56

Assays for the Degradation of Misfolded Proteins in Cells

Published on: August 28, 2016

11.7K

Inhibition of Sp1 functions by its sequestration into PML nuclear bodies

June Li1, Wen-Xin Zou1, Kun-Sang Chang1

  • 1Department of Translational Molecular Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America.

Plos One
|April 15, 2014
PubMed

Insights

Promyelocytic leukemia (PML) nuclear bodies sequester the Sp1 transcription factor, reducing its gene-regulating activity. This PML-mediated sequestration mechanism offers new insights into gene expression control.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Genetics

Background:

  • Promyelocytic leukemia nuclear bodies (PML NBs) are nuclear structures involved in various cellular functions, including gene expression regulation.
  • The precise mechanisms by which PML NBs influence gene expression are not fully understood.

Purpose of the Study:

  • To investigate the role of PML NBs in regulating the activity of the Sp1 transcription factor.
  • To elucidate the molecular mechanisms underlying PML-mediated regulation of Sp1.

Main Methods:

  • Chromatin immunoprecipitation (ChIP) assays to assess Sp1 binding to target gene promoters.
  • Immunofluorescence staining to visualize the co-localization of PML and Sp1.
  • Co-fractionation studies to determine the association of PML and Sp1 within the nuclear matrix.
  • SUMOylation assays to evaluate the effect of PML on Sp1 modification.

Main Results:

  • Induced expression of PML led to the recruitment of Sp1 into PML NBs.
  • PML expression significantly reduced Sp1 binding to its target gene promoters.
  • PML promoted SUMOylation of Sp1 in a RING-motif-dependent manner.
  • SUMOylation of Sp1 facilitated its interaction with PML and recruitment into PML NBs.

Conclusions:

  • PML regulates gene expression by sequestering the Sp1 transcription factor into PML NBs.
  • PML-mediated SUMOylation of Sp1 is a key mechanism for its recruitment into PML NBs.
  • This study reveals a novel pathway for gene expression control involving PML NBs and Sp1.

More Related Videos

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins11:34

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins

Published on: August 9, 2019

5.8K
Inducible and Reversible Dominant-negative DN Protein Inhibition08:35

Inducible and Reversible Dominant-negative DN Protein Inhibition

Published on: January 7, 2019

7.7K

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...
4.0K
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
2.5K
Chromatin Structure Regulates pre-mRNA Processing02:41

Chromatin Structure Regulates pre-mRNA Processing

In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
6.6K
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
10.2K
Eukaryotic Transcription Inhibitors01:52

Eukaryotic Transcription Inhibitors

Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
9.1K
piRNA - Piwi-interacting RNAs02:57

piRNA - Piwi-interacting RNAs

PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
6.1K