Premium
Phosphorylative neuromodulation of the regulatory subunit of cyclic AMP‐dependent protein kinase type II in skeletal muscle
Author(s) -
McLane J. A.,
Squinto S. P.,
Yeoh H. C.,
Held I. R.
Publication year - 1985
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490140208
Subject(s) - phosphorylation , dephosphorylation , denervation , cytosol , protein kinase a , protein subunit , phosphatase , kinase , chemistry , biochemistry , enzyme , medicine , biology , endocrinology , gene
The phosphorylative neuromodulation of the regulatory subunit of protein kinase type II (R‐II) in cytosolic fractions from denervated and sham‐operated, contralateral soleus muscles of the rat was evaluated. The denervation‐induced increase in the 32 P‐phosphorylation of R‐II is not related to an increased dephosphorylation by cation‐dependent or cation‐independent protein phosphatases in the cytosolic fractions. The level of 32 P‐phosphorylation of an exogenous heptapeptide substrate (Kemptide) by dissociated catalytic subunits of cyclic AMP‐dependent protein kinase in cytosolic fractions from denervated and sham‐operated solei did not differ. Also, no change in the concentration of cytosolic R‐II assessed by competitive enzyme‐linked immunosorbent assays (ELISA) was found after denervation. However, the in vitro 32 P‐phosphorylation of R‐II in these samples was increased. Taken together, our results suggest that the increased availability of autophosphorylatable sites reflects an in vivo modulation of R‐II phosphorylation rather than a significant change in total R‐II content.