PROSITE documentation PDOC51490KHA domain profile
Potassium channels take part in important processes of higher plants, including opening and closing of stomatal pores and leaf movement. Inward rectifying potassium (K(+)in) channels play an important role in turgor regulation and ion uptake in higher plants. All of them comprise, from their N-terminal to their C-terminal ends: a short hydrophilic region, a hydrophobic region structurally analogous and partially homologous to the transmembrane domain of voltage-gated animal channels from the Shaker superfamily, a putative cyclic nucleotide-binding domain (see <PDOC00691>), and a conserved C-terminal KHA domain. Between these last two regions, some of them (AKT1, AKT2 and SKT1) contain an ankyrin-repeat domain (see <PDOC50088>) with six repeats homologous to those of human erythrocyte ankyrin. The KHA domain is unique to plant K(+)in channels. The KHA domain contains two high-homology blocks enriched for hydrophobic and acidic residues, respectively. The KHA domain is essential for interaction of plant K(+)in channels. The KHA domain mediates tetramerization and/or stabilization of the heteromers [1,2,3].
Some proteins known to contain a KHA domain are listed below:
- Arabidopsis thaliana AKT1.
- Arabidopsis thaliana AKT2/3.
- Arabidopsis thaliana KAT1.
- Arabidopsis thaliana KAT2.
- Potato KST1.
- Potato SKT1.
- Potato SKT2.
- Potato SKT3.
The profile we developed covers the entire KHA domain.
Last update:April 2010 / First entry.
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PROSITE method (with tools and information) covered by this documentation:
| 1 | Authors | Ehrhardt T. Zimmermann S. Mueller-Roeber B. |
| Title | Association of plant K+(in) channels is mediated by conserved C-termini and does not affect subunit assembly. | |
| Source | FEBS Lett. 409:166-170(1997). | |
| PubMed ID | 9202139 |
| 2 | Authors | Daram P. Urbach S. Gaymard F. Sentenac H. Cherel I. |
| Title | Tetramerization of the AKT1 plant potassium channel involves its C-terminal cytoplasmic domain. | |
| Source | EMBO J. 16:3455-3463(1997). | |
| PubMed ID | 9218788 | |
| DOI | 10.1093/emboj/16.12.3455 |
| 3 | Authors | Zimmermann S. Hartje S. Ehrhardt T. Plesch G. Mueller-Roeber B. |
| Title | The K+ channel SKT1 is co-expressed with KST1 in potato guard cells--both channels can co-assemble via their conserved KT domains. | |
| Source | Plant J. 28:517-527(2001). | |
| PubMed ID | 11849592 |
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