Identification of ischemia-regulated phosphorylation sites in connexin43: A possible target for the antiarrhythmic peptide analogue rotigaptide (ZP123)
Identification of ischemia-regulated phosphorylation sites in connexin43: A possible target for the antiarrhythmic peptide analogue rotigaptide (ZP123)
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DOI：
10.1016/j.yjmcc.2006.03.005
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发表时间：
2006-06-01
影响因子：
5
通讯作者：
Kjolbye, Anne Louise
中科院分区：
文献类型：
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作者：
Axelsen, Lene N.;Stahlhut, Martin;Kjolbye, Anne Louise
以往的研究表明，连接蛋白43(Cx43)的去磷酸化与缝隙连接通讯的解偶联有关，缝隙连接通讯解偶联在缺血性室性心动过速的发生中起重要作用。我们研究了在没有和存在抗心律失常多肽类似物罗替加普肽(以前称为ZP123)的情况下，全脑缺血期间Cx43磷酸化的变化。用基质辅助激光解吸电离质谱仪和高效电喷雾电离串联质谱仪对从大鼠离体心纯化的Cx43进行了磷酸化分析。在非缺血条件下，在Cx43中发现了13个不同的丝氨酸磷酸化位点，其中3个以前没有被描述过。在缺血的前7分钟内，Ser306完全去磷酸化，而Ser330变为磷酸化。在缺血15到30分钟之间，发生缝隙连接解偶联的关键时间间隔，Ser297和Ser368也完全去磷酸化。在同一时间段，所有未经治疗的心脏都出现了心搏停止。在缺血30min时，罗替加肽可显著延长缺血引起的停搏时间，并抑制Ser297和Ser368的去磷酸化。我们的结果提示，Ser297和Scr368的磷酸化可能参与了Cx43在缺血时的功能门控，并可能是Rotigapide信号的下游靶点。(C)2006 Elsevier Inc.保留所有权利。
Previous studies suggest that dephosphorylation of connexin43 (Cx43) is related to uncoupling of gap junction communication, which plays an important role in the genesis of ischemia-induced ventricular tachycardia. We studied changes in Cx43 phosphorylation during global ischemia in the absence and presence of the antiarrhythmic peptide analogue rotigaptide (formerly known as ZP123). Phosphorylation analysis was performed on Cx43 purified from isolated perfused rat hearts using matrix-assisted laser desorption/ionization mass spectrometry and liquid chromatography electrospray ionization tandem mass sliectrometry. Thirteen different serine phosphorylation sites were identified in Cx43 during non-ischemic conditions, three of which had not previously been described. Within the first 7 min of ischemia, Ser306 became fully dephosphorylated whereas Ser330 became phosphorylated. Between 15 and 30 min of ischemia, the critical time interval where gap junction uncoupling occurs, Ser297 and Ser368 also became fully dephosphorylated. During the same time period, all untreated hearts developed asystole. Treatment with rotigaptide significantly increased the time to ischemia-induced asystole and suppressed dephosphorylation of Ser297 and Ser368 at 30 min of ischernia. Our results suggest that phosphorylation of Ser297 and Scr368 may be involved in functional gating of Cx43 during ischemia and may be possible downstream targets for rotigaptide signaling. (c) 2006 Elsevier Inc. All rights reserved.