Intracellular artificial supramolecules based on de novo designed Y15 peptides

Area of Science:

• Biomaterials Science
• Molecular Biology
• Cell Biology

Background:

• De novo designed self-assembling peptides (SAPs) are advanced building blocks for supramolecular biomaterials.
• Applications include scaffolds for tissue culture and vaccine adjuvants, but intracellular use remains largely unexplored.

Purpose of the Study:

• To report a novel self-assembling peptide (Y15) capable of forming functional protein assemblies within living cells.
• To demonstrate the potential of Y15 for intracellular bottom-up synthesis of protein structures.

Main Methods:

• Y15 peptide was designed to form beta-sheet structures.
• Superfolder green fluorescent protein (sfGFP) fused to Y15 was used to visualize intracellular assembly.
• Fluorescence anisotropy and pull-down assays validated Y15 self-assembly.
• Intracellular Nck assembly reconstitution and subsequent N-WASP-mediated actin polymerization were analyzed.

Main Results:

• Y15 peptide self-assembles into beta-sheet structures within mammalian cells, forming observable fluorescent puncta when fused with sfGFP.
• The Y15 platform successfully reconstituted intracellular Nck protein assemblies.
• Artificial Nck clusters induced neural Wiskott-Aldrich syndrome protein (N-WASP)-mediated actin polymerization.

Conclusions:

• Y15 is a functional self-assembling peptide for intracellular applications.
• This platform facilitates the bottom-up synthesis of functional protein assemblies in living cells.
• The study evaluates the impact of Nck domain valency and density on actin polymerization.