Related Experiment Video
Updated: Aug 1, 2025
10:28
Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers
Published on: September 20, 2018
6.5K
MORC proteins regulate transcription factor binding by mediating chromatin compaction in active chromatin regions
Zhenhui Zhong1, Yan Xue1,2, C Jake Harris1,3
1Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA, 90095, USA.
Genome Biology
|April 26, 2023
Summary
Microrchidia (MORC) proteins compact chromatin and repress gene expression independently of RNA-directed DNA methylation. These MORC proteins are crucial for gene regulation, especially during stress conditions.
Area of Science:
- Molecular Biology
- Genetics
- Plant Science
Background:
- Microrchidia (MORC) proteins are conserved GHKL-type ATPases.
- Arabidopsis MORC proteins are involved in RNA-directed DNA methylation (RdDM) and gene silencing.
- MORC proteins possess RdDM-independent functions with unknown mechanisms.
Purpose of the Study:
- Investigate MORC binding regions outside the RdDM pathway.
- Elucidate the mechanisms of MORC's RdDM-independent functions.
Main Methods:
- Analysis of MORC binding regions not associated with RdDM.
- Assessing chromatin compaction and DNA accessibility.
- Evaluating gene expression regulation.
Main Results:
- MORC proteins compact chromatin and reduce DNA accessibility.
- MORC proteins repress gene expression, particularly under stress.
- MORC proteins can regulate transcription factors, forming feedback loops.
Conclusions:
- MORC-mediated chromatin compaction and transcription regulation mechanisms elucidated.
- MORC proteins play a significant role in stress-induced gene regulation.
Related Concept Videos
02:04Co-activators and Co-repressors
7.4K
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
7.4K
02:36RNA Polymerase II Accessory Proteins
9.3K
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
9.3K
02:23Master Transcription Regulators
7.0K
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
7.0K
02:16Transcription Factors
76.2K
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
76.2K
02:41Chromatin Structure Regulates pre-mRNA Processing
7.1K
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...
The chromatin structure, especially...
7.1K
02:13Cooperative Binding of Transcription Regulators
6.5K
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form...
6.5K