The expression of rice vacuolar TPK channels genes restores potassium uptake in E. coli mutant strain LB2003

• Published in: Cytology and genetics Vol. 49; no. 1; pp. 1 - 5
• Main Authors: Isayenkov, S. V., Maathuis, F. J. M.
• Format: Journal Article
• Language: English
• Published: Heidelberg Allerton Press 2015
• Subjects: Biomedical and Life Sciences; Biomedicine; Human Genetics; potassium; two pore K channels; vacuole; TPK
• ISSN: 0095-4527; 1934-9440
• DOI: 10.3103/S0095452715010053

The rice genome encodes three different isoforms of two pore potassium channels (TPKs). Recently, the characteristics and features of some rice TPK channels (OsTPKa and OsTPKb) were reported. In order to further evaluate the functional features of these channels, two of the three rice isoforms and one Arabidopsis isoform (AtTPK1) were cloned and expressed in the mutant
E. coli
strain—LB2003. The E coli LB2003 strain lacks K
+
uptake systems and thus is incapable of growing on low external K
+
concentrations. The expression of channels in bacteria was confirmed by RT-PCR. Our results show that expression of these channels in the bacterial mutant restored the LB2003 growth on low K
+
media. The analysis of potassium uptake exhibited elevated levels of K+ uptake in the three types of TPK transformants. Our data suggest that these plant vacuolar channels can form functional potassium transport systems in bacterial cells.