Annexin 2 has an essential role in actin-based macropinocytic rocketing.
Curr Biol
; 11(14): 1136-41, 2001 Jul 24.
Article
em En
| MEDLINE
| ID: mdl-11509239
ABSTRACT
Annexin 2 is a Ca(2+) binding protein that binds to and aggregates secretory vesicles at physiological Ca(2+) levels [1] and that also associates Ca(2+) independently with early endosomes [2, 3]. These properties suggest roles in both exocytosis and endocytosis, but little is known of the dynamics of Annexin 2 distribution in live cells during these processes. We have used evanescent field microscopy to image Annexin 2-GFP in live, secreting rat basophilic leukemia cells and in cells performing pinocytosis. Although we found no evidence of Annexin 2 involvement in exocytosis, we observed an enrichment of Annexin 2-GFP in actin tails propeling macropinosomes. The association of Annexin 2-GFP with rocketing macropinosomes was specific because Annexin 2-GFP was absent from the actin tails of rocketing Listeria. This finding suggests that the association of Annexin 2 with macropinocytic rockets requires native pinosomal membrane. Annexin 2 is necessary for the formation of macropinocytic rockets since overexpression of a dominant-negative Annexin 2 construct abolished the formation of these structures. The same construct did not prevent the movement of Listeria in infected cells. These results show that recruitment of Annexin 2 to nascent macropinosome membranes 16656is an essential prerequisite for actin polymerization-dependent vesicle locomotion.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pinocitose
/
Actinas
/
Anexina A2
Limite:
Animals
Idioma:
En
Revista:
Curr Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos