The human phospholamban Arg14-deletion mutant localizes to plasma membrane and interacts with the Na/K-ATPase.
The human phospholamban Arg14-deletion mutant localizes to plasma membrane and interacts with the Na/K-ATPase.
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DOI：
10.1016/j.yjmcc.2011.11.012
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发表时间：
2012-03
影响因子：
5
通讯作者：
Kranias EG
中科院分区：
文献类型：
--
作者：
Haghighi K;Pritchard T;Bossuyt J;Waggoner JR;Yuan Q;Fan GC;Osinska H;Anjak A;Rubinstein J;Robbins J;Bers DM;Kranias EG
在人类和实验性心力衰竭中，心肌细胞钙处理的抑制通常归因于肌浆网（SR）功能受损。磷蛋白（PLN）是SR和心功能的关键调节因子，人类PLN突变与扩张型心肌病（DCM）有关。我们之前报道了DCM患者中高度保守的氨基酸残基精氨酸14（核酸39、40和41）的缺失。这种基本氨基酸在维持PLN中PKA磷酸化Ser 16的上游共识序列中很重要。为了评估这种突变PLN的功能，我们将PLN- r14del引入到PLN缺失小鼠的心肌细胞中。与pln敲除基因（PLN-KO）相比，表达突变PLN-R14Del蛋白水平与野生型相似的转基因系对草酸盐促进的SR钙摄取的初始速率没有抑制作用。与PLN-KO类似，PLN-R14Del心肌细胞的收缩参数和钙动力学也保持高度刺激，异丙肾上腺素没有进一步刺激这些超收缩的基础参数。共聚焦显微镜显示，PLN-R14Del未能与SERCA2a共定位，这与SR ca转运和收缩性缺乏抑制一致。此外，PLN-R14Del不像WT-PLN那样与SERCA2a共免疫沉淀，而是与肌层Na/ k - atp酶（NKA）共免疫沉淀，并刺激NKA活性。此外，在HEK细胞中的研究表明，PLN-R14Del-YFP与NKAα1- cfp之间存在显著的荧光共振能量转移，但与NKA调节因子phospholemman之间没有。尽管PLN-R14Del基因的心脏功能增强（与pln基因敲除的心脏一样），但与PLN-KO基因不同的是，心肌肥大伴随着Akt和MAPK通路的激活。因此，在缺乏内源性PLN的情况下，人类PLN- r14del错误地传递到肌膜，并改变NKA活性，导致心脏重塑。
Depressed Ca-handling in cardiomyocytes is frequently attributed to impaired sarcoplasmic reticulum (SR) function in human and experimental heart failure. Phospholamban (PLN) is a key regulator of SR and cardiac function, and PLN mutations in humans have been associated with dilated cardiomyopathy (DCM). We previously reported the deletion of the highly conserved amino acid residue arginine 14 (nucleic acids 39, 40 and 41) in DCM patients. This basic amino acid is important in maintaining the upstream consensus sequence for PKA phosphorylation of Ser 16 in PLN. To assess the function of this mutant PLN, we introduced the PLN-R14Del in cardiac myocytes of the PLN null mouse. Transgenic lines expressing mutant PLN-R14Del at similar protein levels to wild types exhibited no inhibition of the initial rates of oxalate-facilitated SR Ca uptake compared to PLN-knockouts (PLN-KO). The contractile parameters and Ca-kinetics also remained highly stimulated in PLN-R14Del cardiomyocytes, similar to PLN-KO, and isoproterenol did not further stimulate these hyper-contractile basal parameters. Consistent with the lack of inhibition on SR Ca-transport and contractility, confocal microscopy indicated that the PLN-R14Del failed to co-localize with SERCA2a. Moreover, PLN-R14Del did not co-immunoprecipitate with SERCA2a (as did WT-PLN), but rather co-immunoprecipitated with the sarcolemmal Na/K-ATPase (NKA) and stimulated NKA activity. In addition, studies in HEK cells indicated significant fluorescence resonance energy transfer between PLN-R14Del-YFP and NKAα1-CFP, but not with the NKA regulator phospholemman. Despite the enhanced cardiac function in PLN-R14Del hearts (as in PLN-knockouts), there was cardiac hypertrophy (unlike PLN-KO) coupled with activation of Akt and the MAPK pathways. Thus, human PLN-R14Del is misrouted to the sarcolemma, in the absence of endogenous PLN, and alters NKA activity, leading to cardiac remodeling.
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DOI：
10.1111/j.1749-6632.1998.tb08256.x
发表时间：
1998-01-01
期刊：
CARDIAC SARCOPLASMIC RETICULUM FUNCTION AND REGULATION OF CONTRACTILITY
影响因子：
--
作者：
Chu, GX;Ferguson, DG;Kranias, EG
通讯作者：
Kranias, EG
影响因子：
4.8
作者：
Krenz, Maike;Sadayappan, Sakthivel;Robbins, Jeffrey
通讯作者：
Robbins, Jeffrey
影响因子：
15.9
作者：
Kadambi, VJ;Ponniah, S;Kranias, EG
通讯作者：
Kranias, EG
影响因子：
20.1
作者：
Luo, WS;Wolska, BM;Kranias, EG
通讯作者：
Kranias, EG
影响因子：
3
作者：
Gianni, D;Chan, J;Hajjar, RJ
通讯作者：
Hajjar, RJ