| RRC ID |
65618
|
| 著者 |
Tsujii M, Kera K, Hamamoto S, Kuromori T, Shikanai T, Uozumi N.
|
| タイトル |
Evidence for potassium transport activity of Arabidopsis KEA1-KEA6.
|
| ジャーナル |
Sci Rep
|
| Abstract |
Arabidopsis thaliana contains the putative K+ efflux transporters KEA1-KEA6, similar to KefB and KefC of Escherichia coli. KEA1-KEA3 are involved in the regulation of photosynthetic electron transport and chloroplast development. KEA4-KEA6 mediate pH regulation of the endomembrane network during salinity stress. However, the ion transport activities of KEA1-KEA6 have not been directly characterized. In this study, we used an E. coli expression system to examine KEA activity. KEA1-KEA3 and KEA5 showed bi-directional K+ transport activity, whereas KEA4 and KEA6 functioned as a K+ uptake system. The thylakoid membrane-localized Na+/H+ antiporter NhaS3 from the model cyanobacterium Synechocystis is the closest homolog of KEA3. Changing the putative Na+/H+ selective site of KEA3 (Gln-Asp) to that of NhaS3 (Asp-Asp) did not alter the ion selectivity without loss of K+ transport activity. The first residue in the conserved motif was not a determinant for K+ or Na+ selectivity. Deletion of the possible nucleotide-binding KTN domain from KEA3 lowered K+ transport activity, indicating that the KTN domain was important for this function. The KEA3-G422R mutation discovered in the Arabidopsis dpgr mutant increased K+ transport activity, consistent with the mutant phenotype. These results indicate that Arabidopsis KEA1-KEA6 act as K+ transport systems, and support the interpretation that KEA3 promotes dissipation of ΔpH in the thylakoid membrane.
|
| 巻・号 |
9(1)
|
| ページ |
10040
|
| 公開日 |
2019-7-11
|
| DOI |
10.1038/s41598-019-46463-7
|
| PII |
10.1038/s41598-019-46463-7
|
| PMID |
31296940
|
| PMC |
PMC6624313
|
| MeSH |
Antiporters / metabolism
Arabidopsis / genetics
Arabidopsis / metabolism*
Arabidopsis Proteins / genetics
Arabidopsis Proteins / metabolism
Ion Transport / physiology
Potassium / metabolism*
Potassium-Hydrogen Antiporters / genetics
Potassium-Hydrogen Antiporters / metabolism*
Protein Isoforms / metabolism
|
| IF |
3.998
|
| リソース情報 |
| シロイヌナズナ / 植物培養細胞・遺伝子 |
pda04049 |
