These lead to direct sequence changes of sensors and regulators, eg, changing specificity of stimulus or allowing the regulation of new genes.
Chemo-vaccination-induced T cell responses were robust (up to 3,940 SFU/106 PBMCs), predominantly central memory cells, short-lived (≤22 weeks), and appeared intermittently and with changing specificities.
The effector specificity could be rationally changed by changing the specificity of the conjoined aptamer: when a mutation was introduced into the anti-theophylline aptamer that led to discrimination against theophylline and in favor of 3-methylxanthine (that also differed from theophylline by a single methyl group), the aptamer became solely responsive to 3-methylxanthine in vivo.
Surely this greater specificity and flexibility was of benefit to species in navigating the changing environmental landscape.
Behold the changing scenery.
During this recombination process one of several sets of downstream CH exons replaces the Cµ exons and the intervening sequence is deleted from the chromosome, which results in expression of a new C region without changing the specificity of the IgH variable region [5].
In both cases, changing the specificity of the regulator gene either a kinase or a transcription factor can potentially lead to the loss of essential network connections and also potentially create a large number of new connections.
It could also be argued that since the MDH/LDH system simply involves changing substrate specificity, that the change is not particularly 'neo' but rather a tuning of an existing function.
Indeed, such a plasma membrane localisation caused by substrate binding has been suggested by the work of Kunz et al. [19,20], who, by changing the specificity of a Type I PIPkin (which uses PtdIns4 P as a substrate) to that of Type II PIPkin (which uses PtdIns5P), and vice versa, showed that changing substrate specificity of PIPkins can alter their localisation.
It provides a new direction for future research into changing the specificity of REases.
