%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 }