title: No evidence for calpain I involvement in fodrin rearrangements linked to regulated secretion.
abstract: Stimulation of secretion in chromaffin and parotid acinar cells is associated with dramatic rearrangements of the subplasmalemmal cytoskeleton, notably of fodrin and F-actin. It has been proposed that a proteolytic cleavage of fodrin resulting from an activation of the neutral calcium activated protease (calpain) could be responsible for these changes. Using an affinity-purified anti-alpha-fodrin antibody, several cleavage products of fodrin could clearly be detected following incubation of total cell homogenates from chromaffin and parotid acinar cells with purified calpain I. On the other hand, maximum stimulation of secretion of chromaffin cells by nicotine, and of parotid acinar cells by carbachol plus isoproterenol, was not associated with an increased appearance of cleavage products of fodrin. This result is not compatible with the 'proteolytic cleavage' hypothesis.
authors.affiliation: Abteilung Klinische Biochemie, Zentrum innere Medizin, Göttingen, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Perrin
authors.forename: H D
authors.initials: HD
authors.lastname: Söling
mesh_terms: D000313:Adrenal Medulla / Q000201:enzymology*; D000818:Animals; D002154:Calpain / Q000302:isolation & purification / Q000378:metabolism*; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006168:Guinea Pigs; D015151:Immunoblotting; D008840:Microfilament Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D010306:Parotid Gland / Q000201:enzymology*; D010446:Peptide Fragments / Q000302:isolation & purification; D013049:Spectrin
chemical_list: D002154:Calpain; D002352:Carrier Proteins; D008840:Microfilament Proteins; D010446:Peptide Fragments; D013049:Spectrin