Table 1.
A-kinase-anchoring proteins (AKAPs) identified in trophoblasts.
| AKAP (gene nomenclature committee name) | Method of identification | Subcellular localization | Properties/function | CT/ST | Cell-fusion |
|---|---|---|---|---|---|
| D-AKAP1 (AKAP1) | RII affinity chromatography | Outer mitochondrial membrane Endoplasmic reticulum Nuclear envelope | Dual-specific AKAP (D-AKAPs) Binds lamin, PP1 and PDE7A Multiple splice variants | CT | Decrease – T |
| AKAP-KL (AKAP2) | RII affinity chromatography | Actin cytoskeleton Apical membrane | Multiple splice variants | CT/ST | No effect – T |
| AKAP18α, β, γ, δ (AKAP7) | cAMP chromatography | Basolateral (α) Apical (β) Plasma membrane (γ) Cytoplasm (γ) Secretory vesicles (δ) | Targeted to plasma membrane Modulation of Na+ Associate to L-type channels (α) | CT | Decrease – BW |
| AKAP95 (AKAP8) | RII affinity chromatography | Nuclear matrix | Chromosome condensation Binds Eg7, condensin and PDE7A | CT/ST | No effect – T |
| AKAP450 (AKAP9) | RII affinity chromatography | Centrosome Golgi | Binds PDE4D3, PP1, PP2A PKN and PKC𝜀 Targets PKA and PP1 to NMDA-R Multiple splice variants | CT/ST | Decrease – T |
| D-AKAP2 (AKAP10) | cAMP chromatography | Vesicles Peroxisomes Centrosome | D-AKAPs Binds PP1, PP2A | CT | No effect – T |
| Gravin (AKAP12) | RII affinity chromatography | Actin cytoskeleton Cytoplasm | Binds PKC and β-AR | CT | ? – T |
| AKAP-Lbc (AKAP13) | RII affinity chromatography | Cytoplasm | Binds Rho-GEF Couples Gα12 to Rho | CT/ST | ? – T |
| Ezrin | RI/II and cAMP chromatography | Actin cytoskeleton Plasma membrane | D-AKAPs Binds Cx43 Linked to CFTR via EBP50 RISR domain | CT/ST | Decrease – T |
| Myomegalin | RII affinity chromatography | Cytoskeleton Centrosome Cytoplasm | Binds PDE4D | CT | Decrease – T |
| OPA1 | RI affinity chromatography | Inner mitochondrial membrane Mitochondrial intermembrane Lipid droplets | D-AKAPs | CT | ? –T |
Proteins from cytotrophoblasts and syncytiotrophoblast were purified by cAMP or RI-flag and RII-flag affinity chromatography and identified by nanoLC-LTQ Orbitrap Mass Spectrometry analysis of tryptic digests of bands excised from SDS-PAGE. For each AKAP, the subcellular localization, the properties described in literature and the cellular origin of the identification (CT for cytotrophoblast and/or ST for syncytiotrophoblast) were specified. The effect of tested siRNA mediated knockdown on trophoblast fusion was presented from in vitro experiments using primary culture of human trophoblasts (T) or BeWo cells (BW). Silencing of AKAPs not tested on cell fusion was indicated by “?”.