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Updated: Dec 27, 2025
Deciphering Molecular Mechanism of Histone Assembly by DNA Curtain Technique
Published on: March 9, 2022
Enzyme-Instructed Assemblies Enable Mitochondria Localization of Histone H2B in Cancer Cells
Hongjian He1, Jiaqi Guo1, Xinyi Lin1
1Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA, 02453, USA.
Abstract:
Presently, little is known of how the inter-organelle crosstalk impacts cancer cells owing to the lack of approaches that can manipulate inter-organelle communication in cancer cells. We found that a negatively charged, enzyme cleavable peptide (MitoFlag) enables the trafficking of histone protein H2B, a nuclear protein, to the mitochondria in cancer cells. MitoFlag interacts with the nuclear location sequence of H2B to block it from entering the nucleus. A protease on the mitochondria cleaves the Flag from the MitoFlag/H2B complex to form assemblies that retain H2B on the mitochondria and facilitate H2B entering the mitochondria. Adding NLS, replacing aspartic acid by glutamic acid residues, or changing the l- to d-aspartic acid residue on MitoFlag abolishes the trafficking of H2B into mitochondria of HeLa cells. As the first example of the enzyme-instructed self-assembly of a synthetic peptide for trafficking endogenous proteins, this work provides insights for understanding and manipulating inter-organelle communication in cells.
Insights
Researchers developed MitoFlag, a peptide that directs nuclear histone H2B protein to mitochondria in cancer cells. This breakthrough offers new ways to study and control cell communication and its impact on cancer.
Area of Science:
- Cell Biology
- Molecular Biology
- Cancer Research
Background:
- Inter-organelle crosstalk significantly influences cancer cell behavior.
- Current methods to manipulate communication between organelles in cancer cells are limited.
- Understanding organelle communication is crucial for cancer therapy development.
Purpose of the Study:
- To investigate the impact of inter-organelle crosstalk on cancer cells.
- To develop a novel approach for manipulating intracellular communication.
- To explore the trafficking of endogenous proteins between cellular compartments.
Main Methods:
- Design and synthesis of a negatively charged, enzyme-cleavable peptide (MitoFlag).
- Utilizing MitoFlag to facilitate the trafficking of histone H2B from the nucleus to mitochondria.
- Investigating the mechanism of MitoFlag-mediated H2B transport using HeLa cells and analyzing peptide modifications.
Main Results:
- MitoFlag successfully trafficked endogenous histone H2B to mitochondria in cancer cells.
- MitoFlag blocks H2B nuclear import by interacting with its nuclear localization sequence.
- Mitochondrial proteases cleave MitoFlag, enabling H2B retention and entry into mitochondria.
Conclusions:
- This study presents the first enzyme-instructed self-assembly of a synthetic peptide for endogenous protein trafficking.
- The findings provide novel insights into manipulating inter-organelle communication.
- This approach offers a new tool for studying and potentially targeting cancer cell biology.
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