Combinatorial multivalent interactions drive cooperative assembly of the COPII coat

Autor: Viktoriya G. Stancheva, Giulia Zanetti, Xiao-Han Li, Natalia Gomez-Navarro, M. Madan Babu, Elizabeth A. Miller, Balaji Santhanam, Joshua Hutchings
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Journal of Cell Biology
The Journal of Cell Biology
ISSN: 0021-9525
Popis: Using in vitro reconstitution assays and in vivo cellular phenotypes, Stancheva and colleagues dissect the protein interaction network that drives COPII coat assembly during vesicle formation from the endoplasmic reticulum, revealing the importance of multivalent interactions that mutually reinforce each other.
Protein secretion is initiated at the endoplasmic reticulum by the COPII coat, which self-assembles to form vesicles. Here, we examine the mechanisms by which a cargo-bound inner coat layer recruits and is organized by an outer scaffolding layer to drive local assembly of a stable structure rigid enough to enforce membrane curvature. An intrinsically disordered region in the outer coat protein, Sec31, drives binding with an inner coat layer via multiple distinct interfaces, including a newly defined charge-based interaction. These interfaces combinatorially reinforce each other, suggesting coat oligomerization is driven by the cumulative effects of multivalent interactions. The Sec31 disordered region could be replaced by evolutionarily distant sequences, suggesting plasticity in the binding interfaces. Such a multimodal assembly platform provides an explanation for how cells build a powerful yet transient scaffold to direct vesicle traffic.
Databáze: OpenAIRE