The magnitude of activation of the type I and type II forms of cAMP-dependent protein kinase was investigated in estrous follicles and corpora lutea (CL) obtained from ovaries of control rabbits and rabbits injected acutely with human chorionic gonadotropin (hCG). To this end, a chromatographic technique which permitted quantitative evaluation of the in vivo activational state of the two forms ...

To determine the regulatory mechanism for human tyrosine hydroxylase, we examined modulations of the activity of the enzyme from human pheochromocytoma by cyclic AMP-dependent protein kinase, calmodulin-dependent protein kinase II and polyanion. The most remarkable activation was observed when the enzyme was assayed at physiological pH (pH 7) after being subjected to phosphorylation by cyclic A...

Nitric oxide (NO) and cGMP have been implicated in many neuronal functions, including regulation of gene expression, but little is known about the downstream targets of NO/cGMP in the nervous system. We found that type II cGMP-dependent protein kinase (G-kinase), which is widely expressed in the brain, mediated NO- and cGMP-induced activation of the fos promoter in cells of neuronal and glial o...

IFNgamma (interferon-gamma) binding to its cognate receptor results, through JAK (Janus kinase), in direct activation of receptor-bound STAT1 (signal transducer and activator of transcription 1), although there is evidence for additional activation of a MAPK (mitogen-activated protein kinase) pathway. In the present paper, we report IFNgamma-dependent activation of the MEKK4 (MAPK/extracellular...

The ability of interferon-gamma (IFN gamma) to increase class II major histocompatibility complex (class II MHC) gene products in murine macrophages involves activation of Na+/H+ exchange (Prpic V., Yu, S. F., Figueiredo, F., Hollenbach, P. W., Gawdi, G., Herman, B., Uhing, R. J., and Adams, D. O. (1989) Science 244, 469-471). The ability of IFN gamma to increase class II MHC gene product expre...

PEP-19 is a 6 kDa polypeptide that is highly expressed in select populations of neurons that sometimes demonstrate resistance to degeneration. These include the granule cells of the hippocampus and the Purkinje cells of the cerebellum. Its only identified activity to date is that of binding apo-calmodulin. As a consequence, it has been demonstrated to act as an inhibitor of calmodulin-dependent...

We have recently demonstrated that hydrogen peroxide (H2O2) is an extremely potent stimulus of endothelial NO synthase (eNOS) gene expression. The present study was designed to identify the signaling mechanisms mediating this response. Induction of eNOS expression by H2O2 was found to be Ca 21 dependent, inasmuch as it was blocked by BAPTA-AM. Further studies have indicated that Ca/calmodulin-d...

We have recently demonstrated that hydrogen peroxide (H(2)O(2)) is an extremely potent stimulus of endothelial NO synthase (eNOS) gene expression. The present study was designed to identify the signaling mechanisms mediating this response. Induction of eNOS expression by H(2)O(2) was found to be Ca(2+) dependent, inasmuch as it was blocked by BAPTA-AM. Further studies have indicated that Ca(2+)...

Calmodulin plays a vital role in mediating bidirectional synaptic plasticity by activating either calcium/calmodulin-dependent protein kinase II (CaMKII) or protein phosphatase 2B (PP2B) at different calcium concentrations. We propose an allosteric model for calmodulin activation, in which binding to calcium facilitates the transition between a low-affinity [tense (T)] and a high-affinity [rela...