Publications by authors named "Tina E Pastoor"

Studies have suggested that the expression, translocation, and function of alpha4beta2 nicotinic receptors may be modulated by alpha4 subunit phosphorylation, but little direct evidence exists to support this idea. The objective of these experiments was to identify specific serine/threonine residues on alpha4 subunits that are phosphorylated in vivo by cAMP-dependent protein kinase and protein kinase C (PKC). To accomplish this, DNAs coding for human alpha4 subunits containing alanines in place of serines/threonines predicted to represent phosphorylation sites were constructed, and transiently transfected with the DNA coding for wild-type beta2 subunits into SH-EP1 cells.

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This study determined whether the alpha4 subunit of human alpha4beta2 neuronal nicotinic receptors is phosphorylated in situ by cyclic AMP-dependent protein kinase (PKA) or protein kinase C (PKC). To accomplish this, human cloned epithelial cells stably transfected with the human alpha4beta2 nicotinic receptor (SH-EP1-halpha4beta2) were incubated with 32P-orthophosphate to label endogenous ATP stores, and the phosphorylation of alpha4 subunits was determined in the absence or presence of PKA or PKC activation. Autoradiographs and immunoblots indicated that alpha4 subunits immunoprecipitated from a membrane preparation of SH-EP1-halpha4beta2 cells exhibited a single 32P-labeled band corresponding to the alpha4 subunit protein; no signals were associated with untransfected SH-EP1 cells.

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