Evidence for cAMP-dependent protein kinase in the dinoflagellate, Amphidinium operculatum.
Comp Biochem Physiol B Biochem Mol Biol
; 133(3): 317-24, 2002 Nov.
Article
en En
| MEDLINE
| ID: mdl-12431399
ABSTRACT
A cAMP dependent protein kinase (PKA) was identified in the dinoflagellate Amphidinium operculum. In vitro kinase activity towards kemptide, a PKA-specific substrate, was not detectable in crude lysates. However, fractionation of dinoflagellate extracts by gel filtration chromatography showed PKA-like activity toward kemptide at approximately 66 kDa. These findings suggest that possible low molecular mass inhibitors in crude lysates were removed by the gel filtration chromatography. Pre-incubation of extracts with cAMP prior to chromatography resulted in an apparent molecular mass shift in the in vitro kinase assay to 40 kDa. An in-gel kinase assay reflected activity of the free catalytic subunit at approximately 40 kDa. Furthermore, western blotting with an antibody to the human PKA catalytic subunit confirmed a catalytic subunit with a mass of approximately 40 kDa. Results from this study indicate that the PKA in A. operculatum has a catalytic subunit of similar size to that in higher eukaryotes, but with a holoenzyme of a size suggesting a dimeric, rather than tetrameric structure.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Dinoflagelados
/
Proteínas Quinasas Dependientes de AMP Cíclico
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Comp Biochem Physiol B Biochem Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos