Projects per year
Ammonium translocation through biological membranes, by the ubiquitous Amt-Mep-Rh family of transporters, plays a key role in all domains of life. Two highly conserved histidine residues protrude into the lumen of the pore of these transporters, forming the family's characteristic Twin-His motif. It has been hypothesized that the motif is essential to confer the selectivity of the transport mechanism. Here, using a combination of in vitro electrophysiology on Escherichia coli AmtB, in silico molecular dynamics simulations, and in vivo yeast functional complementation assays, we demonstrate that variations in the Twin- His motif trigger a mechanistic switch between a specific transporter, depending on ammonium deprotonation, to an unspecific ion channel activity. We therefore propose that there is no selective filter that governs specificity in Amt-Mep-Rh transporters, but the inherent mechanism of translocation, dependent on the fragmentation of the substrate, ensures the high specificity of the translocation. We show that coexistence of both mechanisms in single Twin-His variants of yeast Mep2 transceptors disrupts the signaling function and so impairs fungal filamentation. These data support a signaling process driven by the transport mechanism of the fungal Mep2 transceptors.
|Number of pages||17|
|Early online date||23 Feb 2022|
|Publication status||Published - 26 Apr 2022|
- candida albicans
- escherichia coli
- sacchoramyces cerevisiae
- ammonium assimilation
- fungal filamentation
- secondary transporter mechanism
FingerprintDive into the research topics of 'Coexistence of ammonium transporter and channel mechanisms in Amt-Mep-Rh Twin-His variants impairs the filamentation signalling capacity of fungal Mep2 transceptors'. Together they form a unique fingerprint.
- 1 Finished
Clash of the Kingdoms: How the quest for nutrients leads to pathogenicity
NERC (Natural Environment Research Council)
31/12/14 → 30/12/17