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Full-Text Articles in Medicine and Health Sciences
Stretch-Induced Calcium Release In Smooth Muscle., Guangju Ji, Robert J Barsotti, Morris E Feldman, Michael I Kotlikoff
Stretch-Induced Calcium Release In Smooth Muscle., Guangju Ji, Robert J Barsotti, Morris E Feldman, Michael I Kotlikoff
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Smooth muscle cells undergo substantial increases in length, passively stretching during increases in intraluminal pressure in vessels and hollow organs. Active contractile responses to counteract increased transmural pressure were first described almost a century ago (Bayliss, 1902) and several mechanisms have been advanced to explain this phenomenon. We report here that elongation of smooth muscle cells results in ryanodine receptor-mediated Ca(2+) release in individual myocytes. Mechanical elongation of isolated, single urinary bladder myocytes to approximately 120% of slack length (DeltaL = 20) evoked Ca(2+) release from intracellular stores in the form of single Ca(2+) sparks and propagated Ca(2+) waves. Ca(2+) …
Characterization Of Subcellular Localization And Stability Of A Splice Variant Of G Alpha I2., Philip B Wedegaertner
Characterization Of Subcellular Localization And Stability Of A Splice Variant Of G Alpha I2., Philip B Wedegaertner
Department of Microbiology and Immunology Faculty Papers
BACKGROUND: Alternative mRNA splicing of alpha(i2), a heterotrimeric G protein alpha subunit, has been shown to produce an additional protein, termed salpha(i2). In the salpha(i2) splice variant, 35 novel amino acids replace the normal C-terminal 24 amino acids of alpha(i2). Whereas alpha(i2) is found predominantly at cellular plasma membranes, salpha(i2) has been localized to intracellular Golgi membranes, and the unique 35 amino acids of salpha(i2) have been suggested to constitute a specific targeting signal. RESULTS: This paper proposes and examines an alternative hypothesis: disruption of the normal C-terminus of alpha(i2) produces an unstable protein that fails to localize to plasma …