Coordinate expression of Ca2+-ATPase slow-twitch isoform and of beta calmodulin-dependent protein kinase in phospholamban-deficient sarcoplasmic reticulum of rabbit masseter muscle.
Modulation of sarcoplasmic reticulum (SR) Ca(2+) transport by endogenous calmodulin-dependent protein kinase II (CaM K II) involves covalent changes of regulatory protein phospholamban (PLB), as a common, but not the only mechanism, in limb slow-twitch muscles of certain mammalian species, such as the rabbit. Here, using immunofluorescent techniques in situ, and biochemical and immunological methods on the isolated SR, we have demonstrated that rabbit masseter, a muscle with a distinct embryological origin, lacks PLB. Accommodating embryological heterogeneity in the paradigm of neural-dependent expression of specific isogenes in skeletal muscle fibers, our results provide novel evidence for the differential expression in the SR of 72 kDa beta components of CaM K II, together with the expression of a slow-twitch sarcoendoplasmic reticulum Ca(2+)-ATPase isoform, both in limb muscle and in the masseter.
Sacchetto
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R
NRC Unit for Muscle Biology and Physiopathology, Department of Experimental Biomedical Sciences, University of Padua, viale G. Colombo 3, 35121, Padua, Italy.
Damiani
E
E
Pallanca
A
A
Margreth
A
A
D000818:Animals; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis* / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D002499:Centrifugation, Density Gradient; D019085:Fluorescent Antibody Technique, Direct; D015151:Immunoblotting; D007527:Isoenzymes / Q000032:analysis / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D008406:Masseter Muscle / Q000201:enzymology* / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch / Q000201:enzymology* / Q000378:metabolism; D010766:Phosphorylation; D011817:Rabbits; D019837:Ryanodine Receptor Calcium Release Channel / Q000032:analysis / Q000096:biosynthesis; D012519:Sarcoplasmic Reticulum / Q000201:enzymology* / Q000378:metabolism; D000099211:Phospholamban
D002135:Calcium-Binding Proteins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D000252:Calcium-Transporting ATPases; D007527:Isoenzymes; D019837:Ryanodine Receptor Calcium Release Channel; D000099211:Phospholamban