Show simple item record

dc.contributor.authorLaohavisit, Anuphonen_US
dc.contributor.authorC. Mortimer, Jenniferen_US
dc.contributor.authorDemidchik, Vadimen_US
dc.contributor.authorM.Coxon, Latyen_US
dc.contributor.authorA. Stancombe, Matthewen_US
dc.contributor.authorMacpherson, Neilen_US
dc.contributor.authorBrownlee, Colinen_US
dc.contributor.authorHofmann, Andreasen_US
dc.contributor.authorA.R. Webb, Alexen_US
dc.contributor.authorMiedema, Henken_US
dc.contributor.authorH. Battey, Nicholasen_US
dc.contributor.authorM. Davies, Juliaen_US
dc.description.abstractRegulation of reactive oxygen species and cytosolic free calcium ([Ca2+]cyt) is central to plant function. Annexins are small proteins capable of Ca2+-dependent membrane binding or membrane insertion. They possess structural motifs that could support both peroxidase activity and calcium transport. Here, a Zea mays annexin preparation caused increases in [Ca2+]cyt when added to protoplasts of Arabidopsis thaliana roots expressing aequorin. The pharmacological profile was consistent with annexin activation (at the extracellular plasma membrane face) of Arabidopsis Ca2+-permeable nonselective cation channels. Secreted annexins could therefore modulate Ca2+ influx. As maize annexins occur in the cytosol and plasma membrane, they were incorporated at the intracellular face of lipid bilayers designed to mimic the plasma membrane. Here, they generated an instantaneously activating Ca2+-permeable conductance at mildly acidic pH that was sensitive to verapamil and Gd3+ and had a Ca2+-to-K+ permeability ratio of 0.36. These results suggest that cytosolic annexins create a Ca2+ influx pathway directly, particularly during stress responses involving acidosis. A maize annexin preparation also demonstrated in vitro peroxidase activity that appeared independent of heme association. In conclusion, this study has demonstrated that plant annexins create Ca2+-permeable transport pathways, regulate [Ca2+]cyt, and may function as peroxidases in vitro.en_US
dc.publisherAmerican Society of Plant Biologistsen_US
dc.publisher.placeUnited Statesen_US
dc.relation.ispartofjournalPlant Cellen_US
dc.subject.fieldofresearchAnalytical Biochemistryen_US
dc.titleZea mays annexins modulate cytosolic free Ca2+ and generate a Ca2+-permeable conductanceen_US
dc.typeJournal articleen_US
dc.type.descriptionC1 - Peer Reviewed (HERDC)en_US
dc.type.codeC - Journal Articlesen_US
gro.rights.copyrightCopyright 2009 American Society of Plant Biologists. Self-archiving of the author-manuscript version is not yet supported by American Scientific Publishers. Please refer to the journal link for access to the definitive, published version or contact the authors for more information.en_AU
gro.hasfulltextNo Full Text

Files in this item


There are no files associated with this item.

This item appears in the following Collection(s)

  • Journal articles
    Contains articles published by Griffith authors in scholarly journals.

Show simple item record