Creatine kinase is an alpha myosin heavy chain 3′UTR mRNA binding protein
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Altered cardiac workload regulates the translation and localization of the α myosin heavy chain (αMyHC) messenger RNA through the 3′ untranslated region (UTR) by protein–RNA interactions. We used the αMyHC 3′UTR from neonatal rat heart tissue in a gel shift analysis to find RNA binding proteins. One was identified by microsequencing as creatine kinase, brain form B (CKBB). The affinity of its binding interaction was evaluated using sense and antisense αMyHC 3′UTR and 3′UTR probes from myosin isoforms of 2B and 2X skeletal muscle. Removal of calcium by the chelating agent EGTA had a potentiating effect on the formation of the CKBB/αMyHC 3′UTR complex in vitro. Varying the concentration of ATP (0.1–1 mM) also enhanced this interaction, suggesting that autophosphorylation of CKBB is taking place. Our novel finding that CKBB, an energy transduction enzyme, binds to the RNA of the 3′UTR of the faster ATP consuming αMyHC suggests a possible regulatory linkage between the metabolic state of the cell and myosin isoform expression.
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- Ingwall J (1993) Adaptive and maladaptive processes: is cardiac failure a consequence of decreased energy reserve? Circulation 87: VII58–VII62.Google Scholar
- Masataka S, Seiryo S, Hiroshi Y, Shin-ichi M and Takashi S (1996) Coupling between myosin ATPase cycle and creatine kinase cycle facilitates cardiac actomyosin sliding in vitro: a clue to mechanical dysfunction during myocardial ischemia. Circulation 93: 310–317.Google Scholar