Profile of RGS expression in single rat atrial myocytes
Profile of RGS expression in single rat atrial myocytes
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DOI：
10.1016/s0167-4781(01)00342-6
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发表时间：
2001-12-03
期刊：
影响因子：
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通讯作者：
Shinaman, JM
中科院分区：
文献类型：
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作者：
Doupnik, CA;Xu, T;Shinaman, JM
“G蛋白信号传导调节因子”（RGS蛋白）是GTP酶激活蛋白大家族的成员，其在各种细胞类型中差异表达并加速异源三聚体G蛋白信号传导的终止。为了鉴定可能影响心房兴奋性自主调节的RGS蛋白，我们筛选了19个RGS基因（RGS亚家族A、B、C和D）在原代培养的单个自发搏动大鼠心房肌细胞中的表达。通过单细胞逆转录-聚合酶链反应（RT-PCR）分析的表达谱显示，7种不同的RGS基因在心房肌细胞中内源性表达，这些基因也在大鼠心房的poly（A）（+）mRNA中鉴定（RGS 2、RGS 3、RGS 4、RGS 6、RGS 10、GAIP和RGSZ 2）。在心房[poly（A）（+）] mRNA中检测到其他RGS转录物，但在单个心房肌细胞中未检测到（RGS 5、RGS 12、RGS 16和RGS 18），因此可能源自心房组织中的非肌细胞来源。单细胞RT-PCR实验还导致RGS 6和GAIP的推定剪接变体的鉴定。使用RGS特异性抗体的免疫细胞化学证实了所选RGS蛋白在培养的心房肌细胞中的存在。这些结果表明，丰富的多样性的RGS表达在心房肌细胞中的G蛋白信号的具体作用还有待确定。心房肌细胞中内源性RGS蛋白的鉴定将促进靶向抑制和/或缺失研究，以确定每种RGS蛋白如何影响心房兴奋性及其通过G蛋白信号传导事件的短期和长期调节。(C)2001 Elsevier Science B. V.保留所有权利。
'Regulators of G protein signaling' (RGS proteins) are members of a large family of GTPase-activating proteins that are differentially expressed in various cell types and accelerate the termination of heterotrimeric G protein signaling. To identify RGS proteins that may affect autonomic regulation of atrial excitability, we screened the expression of nineteen RGS genes (RGS subfamilies A, B, C, and D) in single spontaneously beating rat atrial myocytes maintained in primary culture. Expression profiling by single-cell reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that seven distinct RGS genes are endogenously expressed in atrial myocytes which were also identified in poly(A)(+) mRNA from rat atria (RGS2, RGS3, RGS4, RGS6, RGS10, GAIP, and RGSZ2). Other RGS transcripts were detected in atria] poly(A)(+) mRNA but not single atrial myocytes (RGS5, RGS12, RGS16, and RGS18), and therefore are likely to originate from non-myocyte sources in atrial tissue. The single-cell RT-PCR experiments also led to the identification of putative splice variants for RGS6 and GAIP. Immunocytochemistry using RGS-specific antibodies confirmed the presence of selected RGS proteins in the cultured atrial myocytes. These results demonstrate a rich diversity of RGS expression in atrial myocytes whose specific role in G-protein signaling is yet to be determined. The identification of endogenous RGS proteins in atrial myocytes will facilitate targeted suppression and/or deletion studies to determine how each RGS protein may affect atrial excitability and its short-term and long-term regulation by G-protein signaling events. (C) 2001 Elsevier Science B.V. All rights reserved.