TY  - JOUR
A1  - Becker, Dirk
A1  - Geiger, D.
A1  - Dunkel, M.
A1  - Roller, A.
A1  - Bertl, Adam
A1  - Latz, A.
A1  - Carpaneto, Armando
A1  - Dietrich, Peter
A1  - Roelfsema, M. R. G.
A1  - Voelker, C.
A1  - Schmidt, D.
A1  - Müller-Röber, Bernd
A1  - Czempinski, Katrin
A1  - Hedrich, R.
T1  - AtTPK4, an Arabidopsis tandem-pore K+ channel, poised to control the pollen membrane voltage in a pH- and Ca2+- dependent manner
N2  - The Arabidopsis tandem-pore K+ (TPK) channels displaying four transmembrane domains and two pore regions share structural homologies with their animal counterparts of the KCNK family. In contrast to the Shaker-like Arabidopsis channels (six transmembrane domains/one pore region), the functional properties and the biological role of plant TPK channels have not been elucidated yet. Here, we show that AtTPK4 (KCO4) localizes to the plasma membrane and is predominantly expressed in pollen. AtTPK4 (KCO4) resembles the electrical properties of a voltage-independent K+ channel after expression in Xenopus oocytes and yeast. Hyperpolarizing as well as depolarizing membrane voltages elicited instantaneous K+ currents, which were blocked by extracellular calcium and cytoplasmic protons. Functional complementation assays using a K+ transport-deficient yeast confirmed the biophysical and pharmacological properties of the AtTPK4 channel. The features of AtTPK4 point toward a role in potassium homeostasis and membrane voltage control of the growing pollen tube. Thus, AtTPK4 represents a member of plant tandem-pore-K+ channels, resembling the characteristics of its animal counterparts as well as plant-specific features with respect to modulation of channel activity by acidosis and calcium
Y1  - 2004
SN  - 0027-8424
ER  - 
TY  - JOUR
A1  - Hermanussen, Michael
A1  - Godina, Elena
A1  - Ruehli, Frank J.
A1  - Blaha, Pawel
A1  - Boldsen, Jesper L.
A1  - van Buuren, Stef
A1  - MacIntyre, Matthew
A1  - Aßmann, Christian
A1  - Ghosh, Arunava
A1  - de Stefano, Gian Fra nco
A1  - Sonkin, Valentin D.
A1  - Tresguerres Hernández, Jesús Ángel Fernández
A1  - Meigen, Christof
A1  - Scheffler, Christiane
A1  - Geiger, Cherie L.
A1  - Lieberman, Leslie Sue
T1  - Growth variation, final height and secular trend : proceedings of the 17th Aschauer Soiree, 7th November 2009
N2  - Growth and body height have always been topics interesting to the public. In particular, the stupendous increase of some 15-19 cm in final adult height during the last 150 years in most European countries (the "secular trend"), the concomitant changes in body and head proportions, the tendency towards early onset of sexual maturation, the changes in the age when final height is being reached, and the very recent trend in body mass index, have generated much scientific literature. The marked plasticity of growth in height and weight over time causes problems. Child growth references differ between nations, they tend to quickly become out of date, and raise a number of questions regarding fitting methods, effects caused by selective drop-out, etc. New findings contradict common beliefs about the primary importance of nutritional and health related factors for secular changes in growth. There appears to be a broad age span from mid-childhood to early adolescence that is characterised by a peculiar insusceptibility. Environmental factors that are known to influence growth during this age span appear to have only little or no impact on final height. Major re- arrangements in height occur at an age when puberty has almost been completed and final height has almost been reached, implying that factors, which drive the secular trend in height, are limited to early childhood and late adolescence.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/0018442X
U6  - https://doi.org/10.1016/j.jchb.2010.06.001
SN  - 0018-442X
ER  -