Mechanics of receptor-mediated endocytosis

TLDR

Viruses and bioparticles typically range from tens to hundreds of nanometers and enter cells through ligand–receptor binding on the viral capsid and cell membrane. The study investigates how bioparticle size influences receptor‑mediated endocytosis. The authors model a membrane with diffusive mobile receptors wrapping ligand‑coated cylindrical or spherical particles, and the model can be extended to include clathrin coat effects. The model shows that particles sized tens to hundreds of nanometers can be wrapped and released without clathrin or caveolin, with an optimal size minimizing wrapping time, and the predictions broadly agree with experimental observations.

Abstract

Most viruses and bioparticles endocytosed by cells have characteristic sizes in the range of tens to hundreds of nanometers. The process of viruses entering and leaving animal cells is mediated by the binding interaction between ligand molecules on the viral capid and their receptor molecules on the cell membrane. How does the size of a bioparticle affect receptor-mediated endocytosis? Here, we study how a cell membrane containing diffusive mobile receptors wraps around a ligand-coated cylindrical or spherical particle. It is shown that particles in the size range of tens to hundreds of nanometers can enter or exit cells via wrapping even in the absence of clathrin or caveolin coats, and an optimal particles size exists for the smallest wrapping time. This model can also be extended to include the effect of clathrin coat. The results seem to show broad agreement with experimental observations.