Pollen Tube Growth Regulation by Free Anions Depends on the Interaction between the Anion Channel SLAH3 and Calcium-Dependent Protein Kinases CPK2 and CPK20
Apical growth in pollen tubes (PTs) is associated with the presence of tip-focused ion gradients and fluxes, implying polar localization or regulation of the underlying transporters. The molecular identity and regulation of anion transporters in PTs is unknown. Here we report a negative gradient of cytosolic anion concentration focused on the tip, in negative correlation with the cytosolic Ca2+ concentration. We hypothesized that a possible link between these two ions is based on the presence of Ca2+-dependent protein kinases (CPKs). We characterized anion channels and CPK transcripts in PTs and analyzed their localization. Yellow fluorescent protein (YFP) tagging of a homolog of SLOW ANION CHANNEL-ASSOCIATED1 (SLAH3: YFP) was widespread along PTs, but, in accordance with the anion efflux, CPK2/CPK20/CPK17/CPK34: YFP fluorescence was strictly localized at the tip plasma membrane. Expression of SLAH3 with either CPK2 or CPK20 (but not CPK17/CPK34) in Xenopus laevis oocytes elicited S-type anion channel currents. Interaction of SLAH3 with CPK2/CPK20 (but not CPK17/CPK34) was confirmed by Forster-resonance energy transfer fluorescence lifetime microscopy in Arabidopsis thaliana mesophyll protoplasts and bimolecular fluorescence complementation in living PTs. Compared with wild-type PTs, slah3-1 and slah3-2 as well as cpk2-1 cpk20-2 PTs had reduced anion currents. Double mutant cpk2-1 cpk20-2 and slah3-1 PTs had reduced extracellular anion fluxes at the tip. Our studies provide evidence for a Ca2+-dependent CPK2/CPK20 regulation of the anion channel SLAH3 to regulate PT growth.
%0 Journal Article
%1 RN1086
%A Gutermuth, T.
%A Lassig, R.
%A Portes, M. T.
%A Maierhofer, T.
%A Romeis, T.
%A Borst, J. W.
%A Hedrich, R.
%A Feijó, J. A.
%A Konrad, K. R.
%D 2013
%J Plant Cell
%K fluorescent myOwn protein yellow
%N 11
%P 4525-4543
%R 10.1105/tpc.113.118463
%T Pollen Tube Growth Regulation by Free Anions Depends on the Interaction between the Anion Channel SLAH3 and Calcium-Dependent Protein Kinases CPK2 and CPK20
%U /brokenurl#<Go to ISI>://WOS:000329174400020
%V 25
%X Apical growth in pollen tubes (PTs) is associated with the presence of tip-focused ion gradients and fluxes, implying polar localization or regulation of the underlying transporters. The molecular identity and regulation of anion transporters in PTs is unknown. Here we report a negative gradient of cytosolic anion concentration focused on the tip, in negative correlation with the cytosolic Ca2+ concentration. We hypothesized that a possible link between these two ions is based on the presence of Ca2+-dependent protein kinases (CPKs). We characterized anion channels and CPK transcripts in PTs and analyzed their localization. Yellow fluorescent protein (YFP) tagging of a homolog of SLOW ANION CHANNEL-ASSOCIATED1 (SLAH3: YFP) was widespread along PTs, but, in accordance with the anion efflux, CPK2/CPK20/CPK17/CPK34: YFP fluorescence was strictly localized at the tip plasma membrane. Expression of SLAH3 with either CPK2 or CPK20 (but not CPK17/CPK34) in Xenopus laevis oocytes elicited S-type anion channel currents. Interaction of SLAH3 with CPK2/CPK20 (but not CPK17/CPK34) was confirmed by Forster-resonance energy transfer fluorescence lifetime microscopy in Arabidopsis thaliana mesophyll protoplasts and bimolecular fluorescence complementation in living PTs. Compared with wild-type PTs, slah3-1 and slah3-2 as well as cpk2-1 cpk20-2 PTs had reduced anion currents. Double mutant cpk2-1 cpk20-2 and slah3-1 PTs had reduced extracellular anion fluxes at the tip. Our studies provide evidence for a Ca2+-dependent CPK2/CPK20 regulation of the anion channel SLAH3 to regulate PT growth.
@article{RN1086,
abstract = {Apical growth in pollen tubes (PTs) is associated with the presence of tip-focused ion gradients and fluxes, implying polar localization or regulation of the underlying transporters. The molecular identity and regulation of anion transporters in PTs is unknown. Here we report a negative gradient of cytosolic anion concentration focused on the tip, in negative correlation with the cytosolic Ca2+ concentration. We hypothesized that a possible link between these two ions is based on the presence of Ca2+-dependent protein kinases (CPKs). We characterized anion channels and CPK transcripts in PTs and analyzed their localization. Yellow fluorescent protein (YFP) tagging of a homolog of SLOW ANION CHANNEL-ASSOCIATED1 (SLAH3: YFP) was widespread along PTs, but, in accordance with the anion efflux, CPK2/CPK20/CPK17/CPK34: YFP fluorescence was strictly localized at the tip plasma membrane. Expression of SLAH3 with either CPK2 or CPK20 (but not CPK17/CPK34) in Xenopus laevis oocytes elicited S-type anion channel currents. Interaction of SLAH3 with CPK2/CPK20 (but not CPK17/CPK34) was confirmed by Forster-resonance energy transfer fluorescence lifetime microscopy in Arabidopsis thaliana mesophyll protoplasts and bimolecular fluorescence complementation in living PTs. Compared with wild-type PTs, slah3-1 and slah3-2 as well as cpk2-1 cpk20-2 PTs had reduced anion currents. Double mutant cpk2-1 cpk20-2 and slah3-1 PTs had reduced extracellular anion fluxes at the tip. Our studies provide evidence for a Ca2+-dependent CPK2/CPK20 regulation of the anion channel SLAH3 to regulate PT growth.},
added-at = {2024-02-14T14:38:32.000+0100},
author = {Gutermuth, T. and Lassig, R. and Portes, M. T. and Maierhofer, T. and Romeis, T. and Borst, J. W. and Hedrich, R. and Feijó, J. A. and Konrad, K. R.},
biburl = {https://www.bibsonomy.org/bibtex/2f0ab6da1c9a558aeed9942f8c69d76e7/rainerhedrich_2},
doi = {10.1105/tpc.113.118463},
interhash = {ccee91966c83f8e9852d96448628b0fd},
intrahash = {f0ab6da1c9a558aeed9942f8c69d76e7},
issn = {1040-4651},
journal = {Plant Cell},
keywords = {fluorescent myOwn protein yellow},
note = {282ly
Times Cited:106
Cited References Count:100},
number = 11,
pages = {4525-4543},
timestamp = {2024-02-14T14:38:32.000+0100},
title = {Pollen Tube Growth Regulation by Free Anions Depends on the Interaction between the Anion Channel SLAH3 and Calcium-Dependent Protein Kinases CPK2 and CPK20},
type = {Journal Article},
url = {/brokenurl#<Go to ISI>://WOS:000329174400020},
volume = 25,
year = 2013
}