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The development of dependence on alcohol (as well as on other drugs of abuse) is posited to involve changes in brain chemistry that lead not only to signs of withdrawal [...]

Schafer, Claus, Peter Clapp, Michael J. Welsh, Rainer Benndorf, and John A. Williams. HSP27 expression regulates CCK-induced changes of the actin cytoskeleton in CHO-CCK-A cells. Am. J. Physiol. 277 (Cell Physiol. 46): C1032-C1043, 1999.--We investigated how heat shock protein 27 (HSP27) and its phosphorylation are involved in the action of cholecystokinin (CCK) on the actin cytoskeleton by genetic manipulation of Chinese hamster ovary (CHO) cells stably transfected with the CCK-A receptor. In these cells, as in rat acini, CCK activated p38 mitogen-activated protein (MAP) kinase and increased the phosphorylation of HSP27. This effect could be blocked with the p38 MAP kinase inhibitor SB-203580. Examination by confocal microscopy of cells stained with rhodamine phalloidin showed that CCK dose-dependently induced changes of the actin cytoskeleton, including cell shape changes, which were coincident with actin cytoskeleton fragmentation and formation of actin filament patches in the cells. To further evaluate the role of HSP27, CHO-CCK-A cells were transfected with expression vectors for either wild-type (wt) or mutant (3A, 3G, and 3D) human HSP27. Overexpression of wt-HSP27 and 3D-HSP27 inhibited the effects on the actin cytoskeleton seen after high-dose CCK stimulation. In contrast, overexpression of nonphosphorylatable mutants, 3A- and 3G-HSP27, or inhibition of phosphorylation of HSP27 by preincubation of wt-HSP27 transfected cells with SB-203580 did not protect the actin cytoskeleton. These results suggest that phosphorylation of HSP27 is required to stabilize the actin cytoskeleton and to protect the cells from the effects of high concentrations of CCK. heat shock protein; cholecystokinin; p38 mitogen-activated protein kinase; microfilaments

Alcohol use disorders (AUD) continue to be a concerning health issue worldwide. Harmful alcohol use leads to 2.5 million deaths annually worldwide. Multiple options exist for the management of dependence on alcohol, not all of which are approved by drug-regulating agencies. Current practice in treating AUD does not reflect the diversity of pharmacologic options that have potential to provide benefit, and guidance for clinicians is limited. Few medications are approved for treatment of AUD, and these have exhibited small and/or inconsistent effects in broad patient populations with diverse drinking patterns. The need for continued research into the treatment of this disease is evident in order to provide patients with more specific and effective options. This review describes the neurobiological mechanisms of AUD that are amenable to treatment and drug therapies that target pathophysiological conditions of AUD to reduce drinking. In addition, current literature on pharmacologic (both approved and non-approved) treatment options for AUD offered in the United States and elsewhere are reviewed. The aim is to inform clinicians regarding the options for alcohol abuse treatment, keeping in mind that not all treatments are completely successful in reducing craving or heavy drinking or increasing abstinence. [ABSTRACT FROM AUTHOR]

To understand the requirements for binding to G protein βγ subunits, phage-displayed random peptide libraries were screened using immobilized biotinylated βγ as the target. Selected peptides were grouped into four different families based on their sequence characteristics. One group (group I) had a clear conserved motif that has significant homology to peptides derived from phospholipase C βb (PLC β) and to a short motif in phosducin that binds to G protein β subunits. The other groups had weaker sequence homologies or no homology to the group I sequences. A synthetic peptide from the strongest consensus group blocked activation of PLC by G protein βγ subunits. The peptide did not block βγ-mediated inhibition of voltage-gated calcium channels and had little effect on βγ-mediated inhibition of Gs-stimulated type I adenylate cyclase. Competition experiments indicated that peptides from all four families bound to a single site on βγ. These peptides may bind to a protein-protein interaction 'hot spot' on the surface of βγ subunits that is used by a subclass of effectors. [ABSTRACT FROM AUTHOR]

Initial steps in the identification of the Gs alpha-binding site present in mammalian adenylyl cyclases can be achieved with the use of the yeast genetic system described. It must be stressed that this system serves as a means to identify mutants that are candidates; biochemical analysis of these mutants is a next and necessary step in the confirmation of these phenotypes. The system described can be readily adapted for the isolation of additional classes of mammalian adenylyl cyclase mutants including mutants with altered regulation toward forskolin, catalytic abnormalities, or enhanced sensitivities toward activators. In addition, this system can be employed for the isolation of constitutively active adenylyl cyclase mutants, or by coexpressing other adenylyl cyclase isoforms and their known regulators, mutations in the binding sites for these molecules can be elucidated.