Clathrin is a protein heavily involved in the creation of coated vesicles, it also allows for the trafficking inside cell pathways, mechanisms and regulation. It forms a polyhedral (soccer-ball-shaped) lattice made up of many clathrin molecules that coat a new vesicle as it forms and also helps in protein sorting.
Clathrin subunits is made of polypeptide chains that assemble into a structure called triskelions. Each clathrin triskelions have light chains and heavy chains, which contribute to the function of clathrin coat in aiding vesicle transport. Light chains bind to the actin filament, which helps to move vesicles in the cell. N terminal domain of triskelions binds to adaptor protein, a mediator between triskelions and cargo molecules.
Vesicles do not form spontaneously, but rather, are facilitated by coat-proteins like clathrin. Clathrin doesn't bind directly to a membrane to form vesicles; instead, it binds to adaptor proteins that recognize molecules on a membrane surface. At least 20 different clathrin adaptors have been identified, each recognizing and binding to membrane proteins and phospholipids that are unique to a particular organelle.
During vesicle transport, cargo-loaded vesicles form at a donor compartment, with the help of the specialised clathrin coat. It is one of three types of coating.
- ↑ J.A. Ybe et al., Nature 399 (1999), 371-375.
- ↑ Alberts B. Molecular biology of the cell. 6th ed. New York, NY [u.a.]: Garland Science Taylor &amp;amp; Francis; 2014.
- ↑ RCSB Molecule of the Month by Graham T. Johnson and David Goodsell (April 2007)
- ↑ Trafficking inside cells, pathways, mechanisms and regulation – Nava Segar Springer Lin (c2009) pages 7-9