Microinjected profilin affects cytoplasmic streaming in plant cells by rapidly depolymerizing actin microfilaments.
Curr Biol
; 4(3): 215-9, 1994 Mar 01.
Article
en En
| MEDLINE
| ID: mdl-7922326
ABSTRACT
BACKGROUND:
Cytoplasmic streaming is a conspicuous feature of plant cell behaviour, in which organelles and vesicles shuttle along cytoplasmic strands that contain actin filaments. The mechanisms that regulate streaming and the formation of actin filament networks are largely unknown, but in all likelihood involve actin-binding proteins. The monomeric actin-binding protein, profilin, is a key regulator of actin-filament dynamics in animal cells and it has recently been identified in plants as a pollen allergen. We set out to determine whether plant profilin can act as a monomeric actin-binding protein and influence actin dynamics in plant cells in vivo.RESULTS:
Recombinant birch-pollen profilin was purified by polyproline affinity chromatography and microinjected into Tradescantia blossfeldiana stamen hair cells. After profilin injection, a rapid and irreversible change in cellular organization and streaming was observed within 1-3 minutes the transvacuolar cytoplasmic strands became thinner and snapped, and cytoplasmic streaming ceased. Fluorescein-labelled-phalloidin staining confirmed that this was due to depolymerization of actin filaments. To confirm that the effects observed were due to sequestration of monomeric actin, another monomeric actin-binding protein, DNase I, was injected and found to produce comparable results.CONCLUSIONS:
Profilin can act as a potent regulator of actin organization in living plant cells. Its rapid effect on the integrity of cytoplasmic strands and cytoplasmic streaming supports a model in which organelle movements depend upon microfilaments that exist in dynamic equilibrium with the pool of monomeric actin.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plantas
/
Proteínas Contráctiles
/
Proteínas de Microfilamentos
Idioma:
En
Revista:
Curr Biol
Asunto de la revista:
BIOLOGIA
Año:
1994
Tipo del documento:
Article
País de afiliación:
Reino Unido