title: AKAP12 and AKAP5 form higher-order hetero-oligomers.
abstract: BACKGROUND
  The family of A-kinase-anchoring proteins, AKAPs, constitutes a group of molecular scaffolds that act to catalyze dynamic interactions of protein kinase A, protein kinase C, tyrosine kinases, G-protein-coupled receptors and ion channels. AKAP5 (MW ~47 kDa) and AKAP12 (MW ~191 kDa) homo-oligomerize, but whether or not such AKAPs can hetero-oligomerize into supermolecular scaffolds of increased complexity is unknown.
  
  
  RESULTS
  Affinity chromatography using immobilized AKAPs as "bait" demonstrates unequivocally that AKAP5 and AKAP12 do form minimally hetero-dimers. Steric-exclusion chromatography of AKAP5 and AKAP12 mixtures revealed the existence of very large, supermolecular complexes containing both AKAPs. Docking of AKAP5 to AKAP12 was increased 4-fold by beta-adrenergic agonist stimulation. Overexpression of AKAP12 was found to potentiate AKAP5-mediated Erk1/2 activation in response to stimulation with beta-adrenergic agonist.
  
  
  CONCLUSIONS
  AKAP5 and AKAP12 are capable of forming hetero-oligomeric supermolecular complexes that influence AKAP locale and function.
authors.affiliation: Department of Pharmacology, Health Sciences Center, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794-8651 USA. Gao@pharm.stonybrook.edu.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Gao
authors.forename: Hsien-Yu
authors.initials: HY
authors.lastname: Wang
authors.forename: Craig C
authors.initials: CC
authors.lastname: Malbon