Regulation of myosin light chain kinase during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.
Regulation of myosin light chain kinase during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.
复制标题
DOI：
10.1371/journal.pone.0077248
复制
发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Patel YM
中科院分区：
文献类型：
--
作者：
Woody S;Stall R;Ramos J;Patel YM
肌球蛋白II（MyoII）是3 T3-L1脂肪细胞中胰岛素响应性葡萄糖转运蛋白4（GLUT 4）介导的葡萄糖摄取所必需的。我们以前的研究表明，胰岛素信号通过肌球蛋白轻链激酶（MLCK）刺激MyoIIA的调节轻链（RLC）磷酸化。本文描述的实验描绘了MLCK在胰岛素刺激的葡萄糖摄取过程中的上游调节因子。由于3 T3-L1脂肪细胞表达两种MyoII亚型，我们想确定胰岛素刺激的葡萄糖摄取所需的亚型。使用siRNA的方法，我们证明了60%的减少MyoIIA蛋白表达导致40%的抑制胰岛素刺激的葡萄糖摄取。我们还表明，胰岛素信号刺激MLCK的磷酸化。我们进一步表明，MLCK可以激活钙以及信号通路。我们证明，与单独用胰岛素处理的细胞相比，用钙螯合剂1，2-B（异氨基苯氧基）乙烷-N，N，N '，N'-四乙酸（BAPTA）（在胰岛素存在下）处理的脂肪细胞使胰岛素诱导的MLCK磷酸化降低52%，使MyoIIA的RLC降低45%，并使MyoIIA向质膜的募集降低。我们进一步表明，钙离子载体，A23187单独刺激MLCK的磷酸化和RLC与MyoIIA的胰岛素相同的程度。为了确定可能调节MLCK的信号通路，我们研究了ERK和CaMKII。ERK 2的抑制损害MLCK的磷酸化和胰岛素刺激的葡萄糖摄取。相反，虽然抑制CaMKII确实抑制了与MyoIIA相关的RLC磷酸化，但抑制CAMKIIδ并不损害MLCK磷酸化或转运至质膜或葡萄糖摄取。总的来说，我们的研究结果是第一个描绘的作用，钙和ERK在MLCK的激活，从而在胰岛素刺激的葡萄糖摄取在3 T3-L1脂肪细胞的MyoIIA。
Myosin II (MyoII) is required for insulin-responsive glucose transporter 4 (GLUT4)-mediated glucose uptake in 3T3-L1 adipocytes. Our previous studies have shown that insulin signaling stimulates phosphorylation of the regulatory light chain (RLC) of MyoIIA via myosin light chain kinase (MLCK). The experiments described here delineate upstream regulators of MLCK during insulin-stimulated glucose uptake. Since 3T3-L1 adipocytes express two MyoII isoforms, we wanted to determine which isoform was required for insulin-stimulated glucose uptake. Using a siRNA approach, we demonstrate that a 60% decrease in MyoIIA protein expression resulted in a 40% inhibition of insulin-stimulated glucose uptake. We also show that insulin signaling stimulates the phosphorylation of MLCK. We further show that MLCK can be activated by calcium as well as signaling pathways. We demonstrate that adipocytes treated with the calcium chelating agent, 1,2-b (iso-aminophenoxy) ethane-N,N,N',N'-tetra acetic acid, (BAPTA) (in the presence of insulin) impaired the insulin-induced phosphorylation of MLCK by 52% and the RLC of MyoIIA by 45% as well as impairing the recruitment of MyoIIA to the plasma membrane when compared to cells treated with insulin alone. We further show that the calcium ionophore, A23187 alone stimulated the phosphorylation of MLCK and the RLC associated with MyoIIA to the same extent as insulin. To identify signaling pathways that might regulate MLCK, we examined ERK and CaMKII. Inhibition of ERK2 impaired phosphorylation of MLCK and insulin-stimulated glucose uptake. In contrast, while inhibition of CaMKII did inhibit phosphorylation of the RLC associated with MyoIIA, inhibition of CAMKIIδ did not impair MLCK phosphorylation or translocation to the plasma membrane or glucose uptake. Collectively, our results are the first to delineate a role for calcium and ERK in the activation of MLCK and thus MyoIIA during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.
登录
查看更多内容
影响因子：
3.7
作者：
Fulcher, F. Kent;Smith, Bethany T.;Russ, Misty;Patel, Yashomati M.
通讯作者：
Patel, Yashomati M.
影响因子：
3.9
作者：
Hong, Feng;Haldeman, Brian D.;Jackson, Del;Carter, Mike;Baker, Jonathan E.;Cremo, Christine R.
通讯作者：
Cremo, Christine R.
DOI：
10.1083/jcb.146.1.149
发表时间：
1999-07-12
期刊：
The Journal of cell biology
影响因子：
--
作者：
Nguyen DH;Catling AD;Webb DJ;Sankovic M;Walker LA;Somlyo AV;Weber MJ;Gonias SL
通讯作者：
Gonias SL
影响因子：
4.8
作者：
Konstantopoulos, Nicky;Marcuccio, Seb;Macaulay, S. Lance
通讯作者：
Macaulay, S. Lance
影响因子：
7.5
作者：
Bresnick, AR
通讯作者：
Bresnick, AR