Differentially targeted protein that binds to type I and II regulatory subunits of protein kinase A (PubMed:9065479, PubMed:9182549). Anchors them to the cytoplasmic face of the mitochondrial outer membrane or allows them to reside in the endoplasmic reticulum (PubMed:9065479, PubMed:9182549). Involved in mitochondrial-mediated antiviral innate immunity (By similarity). Promotes translocation of NDUFS1 into mitochondria to regulate mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) activity (PubMed:32072193). Under diabetic conditions, myocardial AKAP1 expression decreases which blocks the translocation of NDUFS1 from the cytosol to mitochondria (PubMed:32072193). Reduction of NDUFS1 in mitochondria decreases ATP production and increases mitochondrial ROS level, which causes mitochondrial dysfunction and cell apoptosis, respectively, thereby leading to cardiac dysfunction (PubMed:32072193). Interacts with SLC8A3 (PubMed:24101730). Interacts with CFAP91. Interacts with CLPB (By similarity). Interacts with NDUFS1 (PubMed:32072193). Does not contain the classic KDEL endoplasmic reticulum-targeting sequence. This explains how it is able to switch its localization, either being in the endoplasmic reticulum or in the mitochondria depending on which N-terminal part begins the isoform. The longest N-terminal part only present in isoform 2 acts as a suppressor of mitochondrial targeting and as an activator of recessive endoplasmic reticulum targeting motif. Does not contain the classic KDEL endoplasmic reticulum-targeting sequence. This explains how it is able to switch its localization, either being in the endoplasmic reticulum or in the mitochondria depending on which N-terminal part begins the isoform. The longest N-terminal part only present in isoform 4 acts as a suppressor of mitochondrial targeting and as an activator of recessive endoplasmic reticulum targeting motif. Does not contain the classic KDEL endoplasmic reticulum-targeting sequence. This explains how it is able to switch its localization, either being in the endoplasmic reticulum or in the mitochondria depending on which N-terminal part begins the isoform. Does not contain the classic KDEL endoplasmic reticulum-targeting sequence. This explains how it is able to switch its localization, either being in the endoplasmic reticulum or in the mitochondria depending on which N-terminal part begins the isoform. Does not contain the classic KDEL endoplasmic reticulum-targeting sequence. This explains how it is able to switch its localization, either being in the endoplasmic reticulum or in the mitochondria depending on which N-terminal part begins the isoform. Does not contain the classic KDEL endoplasmic reticulum-targeting sequence. This explains how it is able to switch its localization, either being in the endoplasmic reticulum or in the mitochondria depending on which N-terminal part begins the isoform. Highest expression in testis, heart, liver, skeletal muscle, intestine and kidney, followed by brain and lung. No expression in spleen. Isoform 1/D-AKAP1A is expressed predominantly in testis whereas isoform 4/D-AKAP1D is expressed primarily in liver (PubMed:9065479). Expression is decreased in hearts of diabetic mice (at protein level) (PubMed:32072193). RII-alpha binding site, predicted to form an amphipathic helix, could participate in protein-protein interactions with a complementary surface on the R-subunit dimer. Knockout in diabetogenic agent streptozotocin-treated mice results in significant cardiac dysfunction which is accompanied by impaired mitochondrial function and increased cardiomyocyte apoptosis.