Kh. Muntz et al., LOCALIZATION OF CARDIAC G(S-ALPHA) IN TRANSGENIC MICE OVEREXPRESSING G(S-ALPHA), Journal of Molecular and Cellular Cardiology, 29(6), 1997, pp. 1649-1653
The biochemical and physiological effects of G(S alpha) activation are
well known; however, little is known about the anatomical localisatio
n of G(S alpha) in the myocardium. Knowledge of the localisation might
yield insights into G protein function in heart. The utility of immun
ocytochemistry using immunofluorescent methods is limited in normal he
arts because of the low expression of G(S alpha). In order to magnify
the G(S alpha) signal, we studied transgenic mice overexpressing myoca
rdial G(S alpha). Immunofluorescent techniques with confocal imaging u
sing rabbit antiserum specific for G(S alpha) were studied in frozen s
ections of mouse left ventricle. G(S alpha) labeling appeared to be lo
calised to the T-tubules and intercalated disks in the G(S alpha) over
expressing mouse hearts, whereas the control mice showed background fl
uorescence with diffuse faint labeling. The localisation of G(S alpha)
to structures involved in calcium handling and membrane conductance p
laces G(S alpha) at a focal point in the regulation of these key funct
ions. (C) 1997 Academic Press Limited.