The resulting spatial "pulling" effect (that is, the bias of target localization toward that of the distractor) was used as a measure of performance.
However, the inability of the BD to direct even a mild bias of apical localization on its own, suggests that the Dia PI 4,5 P2 interaction requires simultaneous binding of an apical cue through an additional domain.
A well-known phenomenon occurs in case of visual-auditory spatial conflict: when a visual stimulus and an auditory stimulus are presented simultaneously but in disparate spatial positions, the perceived location of the sound is shifted towards the visual stimulus (i.e., visual bias of sound localization) [ 4– 6].
Taken together, we show that a partial apical localization bias of Dia by Rho1 binding is significantly enhanced by binding to PI 4,5 P2.
Based on 1000 bootstraps, the localization bias of the peak of TFBS distribution inferred by the TSS (mean ratio = 2.6764 ± 0.0708) is significant higher than that inferred by the start codon (mean ratio = 1.9391 ± 0.0610) (p-value <10-15 <10-15t).
To determine if TSS-based TFBS distribution is more biased than the distribution based on the start codon, we compared the localization bias of the peak which is defined as the ratio of the maximal value of the TFBS frequencies divided by the average value of the TFBS frequencies [ 19].
We found that localization bias of the peak inferred by the TSS (mean ratio = 1.69 ± 0.07) is significant higher than that inferred by the start codon (mean ratio = 1.35 ± 0.05, p-value < 10-15, t-test) supportheg thexistencece of a preferred range of distances from TFBSs to the TSS.
Supporting this notion is the observation that a mutated form of PIP5-kinase, containing an inactive kinase domain, fails to localize to the same membrane domain as the wild-type protein (Fairn et al., 2009), demonstrating that continuous PI 4,5 P2 generation is required to enhance the localization bias of PIP5-kinases.
To further address issues of localization and contamination and to avoid bias due to selective loss of some organelles, liver PNS was fractionated on Percoll gradients.
Comparing the regions of order and disorder reveals a strong bias towards the localization of the interactions within the intrinsically disordered regions.
