Disease relevance of 8-N3-cAMP

• Incubation of H-35 hepatoma cells with vesicle-8-N3-cAMP resulted in increased TAT activity, preceded by the binding of 8-N3-cAMP to the regulatory subunit of type II cAMP-dependent protein kinase [1].

High impact information on 8-N3-cAMP

• Although the average incorporation of 8-N3-cAMP was 0.29 +/- 0.02 (S.E.) pmol/mg protein for control and 0.45 +/- 0.06 pmol/mg protein for neoplastic breast tissue cytosol, this difference does not reflect different cellular concentrations of cAMP receptors since the content of blood protein components is lower in tumor tissue [2].
• Because it can be presumed that protein phosphorylation regulates the functioning of ion channel proteins, we have characterized cAMP-binding proteins photoaffinity labeled with 8-N3-cAMP and have found that, unlike other tissues, the nervous system contains a great variety of binding species [3].
• A stoichiometry of 1 mol of 8-N3-cAMP incorporated per R-monomer was observed for each mutant regulatory subunit as well, even when 2 mol of 8-N3-cAMP were bound per R-monomer; however, the major sites of covalent modification were altered as follows: R(Y371/W), Trp-371; R(E200/D), Tyr-371, and R(F247/Y), Tyr-371 [4].
• Protein kinase I in macrophages demonstrated higher affinity for 8-N3-cAMP (KD = 0.7 nM) than did protein kinase II from either monocytes (KD = 14.5 nM) or macrophages (KD = 4.9 nM) [5].
• Moreover, exposure of T lymphocytes to the cyclic nucleotide derivatives 8-N3-cAMP and 8-Br-cAMP mimicked the effect of adenosine, significantly reducing the time to half-maximal capping [6].

Biological context of 8-N3-cAMP

• Activation of protein kinase isoenzymes under near physiological conditions. Evidence that both types (A and B) of cAMP binding sites are involved in the activation of protein kinase by cAMP and 8-N3-cAMP [7].
• The data indicate that the regulatory subunit contains an ATP regulatory site which inhibits 8-N3 cAMP binding and the release of the catalytic subunit [8].

Anatomical context of 8-N3-cAMP

• Binding of the photoaffinity analogue of cAMP, 8-N3 cAMP, to the regulatory subunits of protein kinases in sonicates obtained from Balb 3T3 and SV 3T3 cells followed by separation on SDS polyacrylamide electrophoresis showed that the amount of RII subunit was approximately equal in the two cell lines [9].
• Cell-free seminal plasma was found to be free of detectable (32P) 8-N3 cAMP-binding proteins [10].
• Concentration-dependent photoaffinity labeling of a band with Mr 60,000 in autoradiograms of gels resulted from incubation of membranes with cyclic 8-azidoadenosine-3',5'-monophosphate (8-N3-[32P]cAMP) followed by exposure to light [11].
• Photoinduced labeling with 8-azido-cyclic AMP of proteins in vesicles from sarcoplasmic reticulum rabbit skeletal muscle has been examined [12].
• Using a radioactively tagged, photoaffinity analog of cAMP, 8-azidoadenosine-3',5'-cyclic monophosphate (8-N3 cAMP) and [gamma32P]ATP, the membrane-binding properties of both the regulatory and catalytic subunits of the cAMP-activated protein kinase of human erythrocyte membranes were investigated [8].

Associations of 8-N3-cAMP with other chemical compounds

• (3) Both native polyacrylamide gel electrophoresis as well as photoaffinity labeling with 8-azido-cyclic AMP demonstrate marked increases in type l cyclic AMP-dPK in the cytosols of cells exposed to agents that induce myeloid differentiation but no increase in TPA-differentiated cells [13].
• Activation of adenylate cyclase, inhibition of cAMP-dependent phosphodiesterase, or the direct addition of the cell-permeable cAMP analog, 8-N3-cAMP, increased occupancy of intracellular cAMP receptors, inhibited IL-2 production, and reduced T-cell proliferation [14].

Gene context of 8-N3-cAMP

• First cyclic AMP and adenosine each blocked binding of both radioactively labelled 8-N3-Ado and 8-N3-cAMP, and second, digestion with V8 proteinase generated identical patterns of peptides from AdoHcyase that had been photolabelled with [32P]8-N3-cAMP and [3H]8-N3-Ado [15].
• Using 8-N3-cAMP photoaffinity labeling, normal and transformed cells were also found to contain equal quantities of a single 42,000 Mr regulatory sub-unit isoenzyme of A-kinase [16].

References