Differential Regulation of Ota and Otb, Two Primary Glycine Betaine Transporters in the Methanogenic Archaeon Methanosarcina mazei Gö1

R. Spanheimer, M. Hoffmann, S. Kögl, S. Schmidt, K. Pflüger, V. Müller
2007 Journal of Molecular Microbiology and Biotechnology  
Methanogenic archaea accumulate glycine betaine in response to hypersalinity, but the regulation of proteins involved, their mechanism of activation and regulation of the corresponding genes are largely unknown. Methanosarcina mazei differs from most other methanoarchaea in having two gene clusters both encoding a potential glycine betaine transporter, Ota and Otb. Western blot as well as quantitative real-time PCR revealed that Otb is not regulated by osmolarity. On the other hand, cellular
more » ... els of Ota increased with increasing salt concentrations. A maximum was reached at 300-500 m M NaCl. Ota concentrations reached a maximum 4 h after an osmotic upshock. Hyperosmolarity also caused an increase in cellular Ota concentrations. In addition to osmolarity Ota expression was regulated by the growth phase. Expression of Ota as well as transport of betaine was downregulated in the presence of glycine betaine.
doi:10.1159/000108656 pmid:17878709 fatcat:membucvohjcclebuydpox2pe7a