Although smAKAP specifically anchors RI isoforms, 56 we diversified our approach by probing dual-specific (d)AKAP1, which recruits RI- and RII-containing PKA holoenzymes to the outer mitochondrial membrane, 80,81 a process found neuroprotective in an AD model.82 Again, RIβWT, but not RIβL50R, co-localized with dAKAP1-EGFP in co-expressing cells, validated by luciferase complementation (Figures S5J–S5L). Here, AKAP1 is linked to Alzheimer disease.