The use of fluorescent probes to differentially label strains and mutants renders the system even more powerful.
In melphalan untreated groups, the expression of different APE1 mutants rendered the same cell survival as wildtype APE1 expression at the time of 72 h (p > 0.05).
This result could be explained by chronic misregulation of neuronal translation in the mutants, rendering the synapses insensitive to enhanced mGluR signaling later in life.
The effects of P61A6 to inhibit proliferation could mainly be ascribed to RhoA, as expression of the RhoA-F geranylgeranylation bypass mutant rendered the cells resistant to inhibition by P61A6.
In addition, the R116W polypeptide was consistently expressed at a lower level than T122K and AGU-Fin precursors, implicating that this mutation may render the mutant AGA polypeptide unstable.
Experiments using different combinations of point mutants rendered FRET values from zero to around 100%, suggesting the geometry of the interaction.
Nevertheless, the identification of residues forming a high affinity binding site, and our finding that cadmium can activate TMEM16A mutants rendered insensitive to calcium, provide key tools for the future study of channel gating processes downstream of TMEM16A's high affinity binding of divalent cations.
One of the product-bound structures described herein is the result of an attempt to cocrystallize the diubiquitin substrate bound to an active site mutant presumed to render the enzyme inactive, instead yielding a cocrystal structure of the enzyme bound to the P-side ubiquitin fragment of the substrate (distal ubiquitin).
The overall interpretation of these studies is more complex, with one report showing that PSEN mutants reduced the ability of GSMs to lower Aβ42 irrespective of potency and structural class, and a second study claiming that only few particularly aggressive PSEN mutants rendered cells resistant to these GSMs [ 97, 101].
One potential problem associated with anti-HIV therapy is the emergence of resistant mutants, which may ultimately render the currently available highly active antiretroviral therapy (HAART) ineffective [ 58– 60].
