However, a paradox in the results is that many of the less severe dpol, dplv, and dpl mutations that retain some dumpy function also introduce premature stop codons that truncate the protein within its extracellular domain.
Nonclassic CLAH is caused by StAR mutations that retain partial activity and may present with a phenotype analogous to familial glucocorticoid deficiency.
In this system, RACK1 inhibits cell migration and overexpression of full length RACK1 or truncation mutations that retain the Gβγ binding, actually inhibit cell migration [ 181].
Discrimination between missense mutations according to location inside or outside DNA-binding motifs, mutations that retain or do not retain transactivation activities, or have dominant-negative effects did not differentiate missense mutations with poorer survival (data not shown).
There are also cases where some nucleotide substitutions in coding regions result in functionally similar proteins (e.g., synonymous mutations or mutations that retain the physical properties of the amino acids).
So far, we have not been able to decouple the fluorescent response from transport activity, but it will be interesting to search for mutations that retain the fluorescent response but are transport-inactive.
Second, individuals with CF with certain "mild" mutations that retain as little as 10% of normal CFTR expression per cell generally do not suffer from lung disease, although other organs such as the vas deferens may be affected.
The C3H/HeJ F9−/− model shows a F9 genotype dependency of inhibitor formation and anaphylaxis that closely mirrors the experience for treatment of human subjects with severe haemophilia B, who are at elevated risk with gene deletions as opposed to mutations that retain endogenous coding information (Verma et al, 2010).
The conserved secondary structure of HMM-defined motifs suggests an evolutionary history that preserved this common aspect, whereas diversification of more polar residues could represent the selection of distinct (unknown) advantages, or the mere accrual of "neutral" mutations that retain the structural integrity of domains.
The two functions can be separated in vitro by mutations that retain sufficient PP1 binding to enable reliable measurement of the non-specific phosphatase activity of the binary PPP1R15-PP1 complex and all but eliminate actin's ability to promote substrate specificity.
