Rodriguez Patricia, Bhogal Moninder S, Colyer John
School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
J Biol Chem. 2003 Oct 3;278(40):38593-600. doi: 10.1074/jbc.C301180200.
The ryanodine receptor of cardiac muscle performs a central role in excitation-contraction coupling. Phosphorylation of the channel on serine 2809 (in rabbit or the corresponding serine 2808 in man) alters function in vitro, although the impact of this in vivo has not been established. We have produced a pair of antisera to the serine 2809 phosphorylation site to aid description of the incidence and consequence of phosphorylation of this receptor. One of these antisera is specific for the serine 2809 phosphorylated form of the cardiac ryanodine receptor; the other antiserum is specific for the serine 2809 dephosphorylated receptor. These antibodies have been used to demonstrate that both protein kinase A and calmodulin-dependent kinase II are capable of phosphorylating serine 2809 in vitro. Both kinases phosphorylate serine 2809 to full stoichiometry, but this is accompanied by the incorporation of more (radioactive) phosphate into the receptor by calmodulin-dependent kinase II than by protein kinase A. These data suggest that calmodulin-dependent kinase II phosphorylates at least four sites in addition to serine 2809 in vitro.
心肌的兰尼碱受体在兴奋-收缩偶联中起核心作用。通道丝氨酸2809位点（兔）或相应的丝氨酸2808位点（人）的磷酸化在体外会改变其功能，尽管其在体内的影响尚未明确。我们制备了一对针对丝氨酸2809磷酸化位点的抗血清，以帮助描述该受体磷酸化的发生率及后果。其中一种抗血清对心肌兰尼碱受体的丝氨酸2809磷酸化形式具有特异性；另一种抗血清对丝氨酸2809去磷酸化受体具有特异性。这些抗体已被用于证明蛋白激酶A和钙调蛋白依赖性激酶II在体外均能够使丝氨酸2809磷酸化。两种激酶均能使丝氨酸2809完全磷酸化，但与蛋白激酶A相比，钙调蛋白依赖性激酶II会使更多（放射性）磷酸基团掺入受体。这些数据表明，在体外，钙调蛋白依赖性激酶II除了使丝氨酸2809磷酸化外，还至少使四个位点磷酸化。
