Identification of sperm-specific proteins that interact with A-kinase anchoring proteins in a manner similar to the type II regulatory subunit of PKA.

The cAMP-dependent protein kinase (PKA) is targeted to specific subcellular compartments through its interaction with A-kinase anchoring proteins (AKAPs). AKAPs contain an amphipathic helix domain that binds to the type II regulatory subunit of PKA (RII). Synthetic peptides containing this amphipathic helix domain bind to RII with high affinity and competitively inhibit the binding of PKA with AKAPs.

Regulation of IL-15-stimulated TNF-alpha production by rolipram.

Agents that increase intracellular cAMP have been shown to reduce joint inflammation in experimental arthritis, presumably by lowering the release of proinflammatory cytokines, such as TNF-alpha. Recent studies suggest that, in joints of patients with rheumatoid arthritis, TNF-alpha release from macrophages is triggered by their interaction with IL-15-stimulated T lymphocytes. In this report, we analyze the effect of rolipram, a cAMP-specific phosphodiesterase inhibitor, on TNF-alpha production in this experimental system.