Chaperones, somatotroph tumors and the cyclic AMP (cAMP)-dependent protein kinase (PKA) pathway.

The cAMP-PKA pathway plays an essential role in the pituitary gland, governing cell differentiation and survival, and maintenance of endocrine function. Somatotroph growth hormone transcription and release as well as cell proliferation are regulated by the cAMP-PKA pathway; cAMP-PKA pathway abnormalities are frequently detected in sporadic as well as in hereditary somatotroph tumors and more rarely in other pituitary tumors. Inactivating variants of the aryl hydrocarbon receptor-interacting protein (AIP)-coding gene are the genetic cause of a subset of familial isolated pituitary adenomas (FIPA). Multiple functional links between the co-chaperone AIP and the cAMP-PKA pathway have been described. This review explores the role of chaperones including AIP in normal pituitary function as well as in somatotroph tumors, and their interaction with the cAMP-PKA pathway.