Please use this identifier to cite or link to this item:
https://hdl.handle.net/2440/109139
Citations | ||
Scopus | Web of Science® | Altmetric |
---|---|---|
?
|
?
|
Type: | Journal article |
Title: | Maize NPF6 proteins are homologs of Arabidopsis CHL1 that are selective for both nitrate and chloride |
Other Titles: | NPF nitrate and chloride transport |
Author: | Wen, Z. Tyerman, S. Dechorgnat, J. Ovchinnikova, E. Dhugga, K. Kaiser, B. |
Citation: | The Plant Cell, 2017; 29(9):00724-00724 |
Publisher: | American Society of Plant Biologists |
Issue Date: | 2017 |
ISSN: | 1040-4651 1532-298X |
Statement of Responsibility: | Zhengyu Wen, Stephen Tyerman, Julie Dechorgnat, Evgenia Ovchinnikova, Kanwarpal Dhugga, Brent N Kaiser |
Abstract: | Nitrate uptake by plant cells requires both high and low-affinity transport activities. Arabidopsis (Arabidopsis thaliana, At) nitrate transporter 1/peptide transporter family (NPF) 6.3 is a dual-affinity plasma membrane transport protein that has both high and low-affinity functions. At-NPF6.3 imports and senses nitrate and is regulated by phosphorylation at Thr-101 (T101). A detailed functional analysis of two maize (Zea mays, Zm) homologs of At-NPF6.3 (Zm-NPF6.6 and Zm-NPF6.4) showed that Zm-NPF6.6 was a pH dependent non-biphasic high-affinity nitrate-specific transport protein. By contrast, maize NPF6.4 was a low-affinity nitrate transporter with efflux activity. When supplied chloride, NPF6.4 switched to a high-affinity chloride selective transporter, while NPF6.6 had only a low-affinity chloride transport activity. Structural predictions identified a nitrate binding His (H362) in NPF6.6 but not in NPF6.4. Mutation of NPF6.4 Tyr-370 to His (Y370H) resulted in saturable high-affinity nitrate transport activity and nitrate selectivity. Loss of H362 in NPF6.6 (H362Y) eliminated both nitrate and chloride transport. Furthermore, alterations to Thr-104, a conserved phosphorylation site in NPF6.6, resulted in a similar high-affinity nitrate transport activity with increased Km whereas equivalent changes in NPF6.4 (T106) disrupted high-affinity chloride transport activity. NPF6 proteins exhibit different substrate specificity in plants and regulate nitrate transport affinity/selectivity using a conserved His residue. |
Keywords: | Arabidopsis Zea mays Chlorides Nitrates Anion Transport Proteins Plant Proteins Gene Expression Regulation, Plant |
Rights: | © 2017 American Society of Plant Biologists. All rights reserved. |
DOI: | 10.1105/tpc.16.00724 |
Grant ID: | http://purl.org/au-research/grants/arc/LP110200878 |
Published version: | http://dx.doi.org/10.1105/tpc.16.00724 |
Appears in Collections: | Aurora harvest 8 Biochemistry publications |
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.