KDC1, a carrot Shaker-like potassium channel, reveals its role as a silent regulatory subunit when expressed in plant cells
Articolo
Data di Pubblicazione:
2008
Citazione:
KDC1, a carrot Shaker-like potassium channel, reveals its role as a silent regulatory subunit when expressed in plant cells / M. Bregante, Y. Yang, E. Formentin, A. Carpaneto, J.I. Schroeder, F. Gambale, F. Lo Schiavo, A. Costa. - In: PLANT MOLECULAR BIOLOGY. - ISSN 0167-4412. - 66:1-2(2008 Jan), pp. 61-72.
Abstract:
The Shaker potassium channels are tetrameric
proteins formed by the assembly of four a-subunits. The
oligomerization can occur among both homo- and heteroa-
subunits. KDC1 is a carrot Shaker-like potassium channel
expressed in the epidermis of plantlet roots and the
protoderm of somatic embryos. KDC1 was previously
characterised electrophysiologically in CHO and Xenopus
oocytes cells, but the experiments performed in these
systems did not provide conclusive evidence that KDC1
forms a functional homomeric channel in plant cells. In this
report, we show that KDC1 localizes to the plasma membrane
of root cells in transgenic tobacco plants transformed
with a KDC1::GFP fusion construct. In tobacco mesophyll
protoplasts, transiently transformed with KDC1::GFP,
KDC1 was present on the endomembrane and the
protoplasts did not show any inward potassium current,
as demonstrated by patch-clamp experiments. The
co-expression of KDC1::GFP with the Arabidopsis thaliana
potassium channel AKT1 in tobacco mesophyll protoplasts
has the effect of shifting KDC1 localization from endomembranes
to the plasma membrane. Patch-clamp
experiments performed on tobacco mesophyll protoplasts
expressing AKT1 alone or in combination with KDC1::GFP showed voltage-activated inward potassium
currents with different properties. In particular, the addition
of Zn2+ to the bath solution induced a clear decrease of the
potassium currents in protoplasts transformed with AKT1
alone, whereas a current potentiation (indicative of KDC1
presence) was observed in protoplasts co-transformed with
AKT1 + KDC1::GFP. Split-Ubiquitin assay experiments
performed in yeast cells confirmed the interaction between
AKT1 and KDC1.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Carrot; GFP; Plasma membrane; Root; Shaker; Split-Ubiquitin
Elenco autori:
M. Bregante, Y. Yang, E. Formentin, A. Carpaneto, J.I. Schroeder, F. Gambale, F. Lo Schiavo, A. Costa
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