Synchronized activation and refolding of influenza hemagglutinin in multimeric fusion machines

Citation
I. Markovic et al., Synchronized activation and refolding of influenza hemagglutinin in multimeric fusion machines, J CELL BIOL, 155(5), 2001, pp. 833-843
Citations number
46
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
155
Issue
5
Year of publication
2001
Pages
833 - 843
Database
ISI
SICI code
0021-9525(20011126)155:5<833:SAAROI>2.0.ZU;2-J
Abstract
At the time of fusion, membranes are packed with fusogenic proteins. Do adj acent individual proteins interact with each other in the plane of the memb rane? Or does each of these proteins serve as an independent fusion machine ? Here we report that the low pH-triggered transition between the initial a nd final conformations of a prototype fusogenic protein, influenza hemagglu tinin (HA), involves a preserved interaction between individual HAs. Althou gh the HAs of subtypes H3 and H2 show notably different degrees of activati on, for both, the percentage of low pH-activated HA increased with higher s urface density of HA, indicating positive cooperativity. We propose that a concerted activation of HAs, together with the resultant synchronized relea se of their conformational energy, is an example of a general strategy of c oordination in biological design, crucial for the functioning of multiprote in fusion machines.