Since the isolation of a cAMP-dependent protein kinase in 1968, information has accumulated regarding the molecular properties and regulation of the purified enzyme. Little direct information is available, however, documenting control in intact cells. Treatment of rat diaphragm with epinephrine or insulin has been reported to alter the cAMP dependency of the protein kinase. The chapter investigates the hormonal regulation of this enzyme in adipose tissue. Binding of cAMP to the regulatory subunit of the inactive protein kinase (RC) causes dissociation of the enzyme into a regulatory subunit cAMP complex (R·cAMP) and an active catalytic subunit. Errors because of the presence of several cell types and problems in the assays for the components given in this chapter have also been considered. Because of these uncertainties, the measurements of protein kinase activation by our procedure may be semiquantitative.
ASJC Scopus subject areas
- Molecular Biology