Cell membrane diversity in noncovalent protein transduction

Area of Science:

• Cell Biology
• Molecular Biology
• Biotechnology

Background:

• Cellular uptake of macromolecules typically requires energy, receptors, or artificial methods.
• Arginine-rich intracellular delivery (AID) peptides have previously shown efficacy in delivering macromolecules into animal and plant cells.
• The application of AID peptides has been confined to animal and plant systems, with their broader applicability unexplored.

Purpose of the Study:

• To investigate the efficacy of AID peptides in mediating non-covalent protein transduction (NPT) across diverse species beyond animals and plants.
• To determine which organisms possess the capability for AID-mediated NPT.
• To elucidate the mechanism of AID-mediated NPT in cyanobacteria and compare it with eukaryotic systems.

Main Methods:

• Screening of representative organisms including cyanobacteria, bacteria, archaea, algae, fungi, and yeasts for NPT capability.
• Analysis of AID peptide internalization mechanisms in cyanobacteria.
• Comparative assessment of protein passage in different eukaryotic groups (algae, fungi).

Main Results:

• Not all organisms demonstrated the capability for protein transduction via AID peptides.
• All tested prokaryotic species (cyanobacteria, bacteria, archaea) exhibited NPT mediated by AID peptides.
• Cyanobacteria utilize an energy-independent pathway, potentially involving macropinocytosis, for AID-mediated NPT.
• Green algae and multicellular fungi proved impermeable to protein passage mediated by AID peptides.

Conclusions:

• AID peptides demonstrate broad applicability for NPT in prokaryotes, challenging previous limitations to animal and plant systems.
• The differential permeability observed between prokaryotes and certain eukaryotes (algae, fungi) provides insights into evolutionary divergence.
• These findings suggest a re-evaluation of the phylogeny of algae and fungi based on their cellular uptake mechanisms.