Mutations at R307 in MloK1, the most conserved residue in the binding pocket of cyclic nucleotide-binding proteins, were not tolerated as these mutants do not form functional channels.
To test if the ΔMovam7 mutants was able to form functional appressoria, appressorium assay was performed and results showed that the ΔMovam7 mutant was unable to form appressoria on the host leaves, whereas plenty of appressoria were found in 52 and 71% of the hyphal tips of the control at 24 and 48 hours post infection (Figure 8C).
Additionally, Kv11.1-mut constructs alone did not produce any measurable tail currents, suggesting that mutant constructs did not form functional channels.
Implications and future directions These findings provide evidence that the Q49X mutant is unable to form functional gap junctions because it is retained intracellularly, in the ER.
To determine whether the I130T and G60S Cx43 mutants had similar capacities to form functional gap junction channels, gap junctional communication-deficient N2A cells were engineered to individually express these mutants.
Thus, although many components of muscle attachments are expressed in these mutants, they often fail to form functional muscle attachments and seem to require PAT-9 for their proper assembly.
The corresponding null mutants have appressoria that are unable to form functional penetration pegs that direct the penetration of the fungus into host plant [ 3, 13, 14].
However, in 2 cases (i.e., V44E and W45S) properly localized mutants have been found to fail to form functional gap junctional channels.
Cx50 mutants that undergo mistrafficking have generally been associated with failure to form functional gap junction channels; however, sometimes even properly trafficked mutants were found to undergo similar consequences.
This study revealed four distinct loss-of-function mechanisms for the mutant hNav1.5 channels (Fig. 7): First, mutants R878C and G1408R were correctly transported to the plasma membrane, but did not form functional channels, suggesting a complete gating/permeation defect.
