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Proteins

Breakthrough in Protein Manipulation: New Peptide-Based Systems for Rapid and Reversible Knock-Down

Strategic Insights

— 1 min read

Researchers from the University of British Columbia have developed a groundbreaking peptide-based system for rapidly and reversibly knocking down non-genetically modified native proteins. This innovative approach harnesses the endogenous lysosome-dependent autophagy system, chaperone-mediated autophagy (CMA), to selectively degrade target proteins. The system consists of a peptide comprising a CMA-targeting signal domain, a protein-binding domain that selectively binds to the target protein, and a cell membrane penetrating domain.

Key Takeaways:

  • The peptide-based system utilizes the endogenous lysosome-dependent autophagy system, CMA, to selectively degrade target proteins.
  • The system consists of a peptide comprising a CMA-targeting signal domain, a protein-binding domain, and a cell membrane penetrating domain.
  • The protein-binding domain selectively binds to the target protein, and the CMA-targeting signal domain delivers the peptide-protein complex into the lysosome for degradation.
  • The cell membrane penetrating domain, such as the HIV-1 Tat protein or the Drosophila melanogaster Antennapedia domain, allows the peptide to penetrate the cellular membrane.
  • The system is capable of rapidly and reversibly knocking down non-genetically modified native proteins.
  • The peptide can be systemically administered to an animal to reduce the cellular expression level of an endogenous target protein.
  • The system has potential applications in treating diseases by reducing the expression level of disease-causing proteins.

Statistics:

  • The peptide-based system targets CMA, a type of autophagy resulting in the selective uptake of substrate proteins in a molecule-by-molecule basis.
  • The CMA-targeting signal domain is essential for inducing CMA and is found in all substrate proteins of CMA to date.
  • The peptide may comprise a CMA-targeting signal (CTS) motif, specifically the pentapeptide KFERQ (SEQ ID NO: 26).
  • The protein-binding domain selectively binds to the target protein, allowing for specific degradation.
  • The system can be used in vitro or in vivo to reduce the intracellular expression level of a target protein.
  • The peptide-based system has potential applications in treating diseases by reducing the expression level of disease-causing proteins.

Sources:

  • Fan, Xuelai. Peptide directed protein knockdown. U.S. Patent Number 12428456, filed November 5, 2021, and published online on September 30, 2025.
  • NewsRx. "Breakthrough in Protein Manipulation: New Peptide-Based Systems for Rapid and Reversible Knock-Down." October 20, 2025.
  • University of British Columbia. "Peptide directed protein knockdown."

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