INVESTIGADORES
YANOVSKY Marcelo Javier
artículos
Título:
Functional and biochemical analysis of the N-terminal domain of phytochrome A
Autor/es:
MATEOS JL, LUPPI JP, OGORODNIKOVA OB, SINESCHEKOV VA, YANOVSKY MJ, BRASLAVSKY SE, GARTNER W, CASAL JJ
Revista:
JOURNAL OF BIOLOGICAL CHEMISTRY
Referencias:
Año: 2006 p. 34421 - 34429
ISSN:
0021-9258
Resumen:
Phytochrome A (phyA) is a versatile plant photoreceptor that
mediates responses to brief light exposures (very low fluence
responses, VLFR) as well as to prolonged irradiation (high irradiance
responses, HIR). We identified the phyA-303 mutant
allele of Arabidopsis thaliana bearing an R384K substitution in
the GAF subdomain of the N-terminal half of phyA. phyA-303phyA-303 mutant
allele of Arabidopsis thaliana bearing an R384K substitution in
the GAF subdomain of the N-terminal half of phyA. phyA-303Arabidopsis thaliana bearing an R384K substitution in
the GAF subdomain of the N-terminal half of phyA. phyA-303phyA-303
showed reduced phyA spectral activity, almost normal VLFR,
and severely impaired HIR. Recombinant N-terminal half oat of
PHYA bearing the phyA-303 mutation showed poor incorporation
of chromophore in vitro, despite the predicted relatively
long distance (>13A˚ ) between the mutation and the closest ring
of the chromophore. Fusion proteins bearing the N-terminal
domain of oat phyA, -glucuronidase, green fluorescent protein,
and a nuclear localization signal showed physiological
activity in darkness and mediated VLFR but not HIR. At equal
protein levels, the phyA-303 mutation caused slightly less activity
than the fusions containing the wild-type sequence. Taken
together, these studies highlight the role of the N-terminal
domain of phyA in signaling and of distant residues of the GAF
subdomain in the regulation of phytochrome bilin-lyase
activity.phyA-303 mutation showed poor incorporation
of chromophore in vitro, despite the predicted relatively
long distance (>13A˚ ) between the mutation and the closest ring
of the chromophore. Fusion proteins bearing the N-terminal
domain of oat phyA, -glucuronidase, green fluorescent protein,
and a nuclear localization signal showed physiological
activity in darkness and mediated VLFR but not HIR. At equal
protein levels, the phyA-303 mutation caused slightly less activity
than the fusions containing the wild-type sequence. Taken
together, these studies highlight the role of the N-terminal
domain of phyA in signaling and of distant residues of the GAF
subdomain in the regulation of phytochrome bilin-lyase
activity.in vitro, despite the predicted relatively
long distance (>13A˚ ) between the mutation and the closest ring
of the chromophore. Fusion proteins bearing the N-terminal
domain of oat phyA, -glucuronidase, green fluorescent protein,
and a nuclear localization signal showed physiological
activity in darkness and mediated VLFR but not HIR. At equal
protein levels, the phyA-303 mutation caused slightly less activity
than the fusions containing the wild-type sequence. Taken
together, these studies highlight the role of the N-terminal
domain of phyA in signaling and of distant residues of the GAF
subdomain in the regulation of phytochrome bilin-lyase
activity.>13A˚ ) between the mutation and the closest ring
of the chromophore. Fusion proteins bearing the N-terminal
domain of oat phyA, -glucuronidase, green fluorescent protein,
and a nuclear localization signal showed physiological
activity in darkness and mediated VLFR but not HIR. At equal
protein levels, the phyA-303 mutation caused slightly less activity
than the fusions containing the wild-type sequence. Taken
together, these studies highlight the role of the N-terminal
domain of phyA in signaling and of distant residues of the GAF
subdomain in the regulation of phytochrome bilin-lyase
activity.-glucuronidase, green fluorescent protein,
and a nuclear localization signal showed physiological
activity in darkness and mediated VLFR but not HIR. At equal
protein levels, the phyA-303 mutation caused slightly less activity
than the fusions containing the wild-type sequence. Taken
together, these studies highlight the role of the N-terminal
domain of phyA in signaling and of distant residues of the GAF
subdomain in the regulation of phytochrome bilin-lyase
activity.phyA-303 mutation caused slightly less activity
than the fusions containing the wild-type sequence. Taken
together, these studies highlight the role of the N-terminal
domain of phyA in signaling and of distant residues of the GAF
subdomain in the regulation of phytochrome bilin-lyase
activity.