Possible interrelationship between changes in F-actin and myosin II, protein phosphorylation, and cell volume regulation in Ehrlich ascites tumor cells.
Possible interrelationship between changes in F-actin and myosin II, protein phosphorylation, and cell volume regulation in Ehrlich ascites tumor cells.
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DOI：
10.1006/excr.2002.5529
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发表时间：
2002-07
影响因子：
3.7
通讯作者：
S. Pedersen;E. Hoffmann
中科院分区：
文献类型：
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作者：
S. Pedersen;E. Hoffmann
埃利希腹水瘤细胞（EATC）的渗透收缩引起肌球蛋白II从胞质移位到皮质区，肿胀引起肌球蛋白II在高尔基体区的浓度。Rho激酶和p38似乎都参与收缩诱导的肌球蛋白II重组。相比之下，先前报道的收缩诱导的肌动蛋白聚合[Pedersen等人（1999）Exp. Cell Res. 252，63-74]不依赖于Rho激酶、p38、肌球蛋白轻链激酶（MLCK）和蛋白激酶C（PKC），因此它们不通过对F-肌动蛋白的作用对收缩激活的转运蛋白发挥作用。然而，随后的F-肌动蛋白解聚，出现MLCK和PKC依赖性，和最初的肿胀诱导的F-肌动蛋白解聚MLCK依赖性，这两种效果显然是次要的激酶介导的细胞体积变化的影响。EATC中的NHE 1通过渗透收缩和丝氨酸/苏氨酸磷酸酶抑制剂Calyculin A（CL-A）激活。这两种刺激导致Rho激酶依赖的肌球蛋白II搬迁到皮质细胞质，但在收缩诱导的F-肌动蛋白聚合相反，CL-A治疗引起轻微的F-肌动蛋白解聚。此外，Rho激酶抑制并没有显着影响NHE 1激活，无论是收缩，也没有CL-A。在F-肌动蛋白和肌球蛋白II，蛋白磷酸化，和细胞体积调节的变化之间可能的相互关系的影响进行了讨论。
Osmotic shrinkage of Ehrlich ascites tumor cells (EATC) elicited translocation of myosin II from the cytosol to the cortical region, and swelling elicits concentration of myosin II in the Golgi region. Rho kinase and p38 both appeared to be involved in shrinkage-induced myosin II reorganization. In contrast, the previously reported shrinkage-induced actin polymerization [Pedersen et al. (1999) Exp. Cell Res. 252, 63-74] was independent of Rho kinase, p38, myosin light chain kinase (MLCK), and protein kinase C (PKC), which thus do not exert their effects on the shrinkage-activated transporters via effects on F-actin. The subsequent F-actin depolymerization, however, appeared MLCK- and PKC-dependent, and the initial swelling-induced F-actin depolymerization was MLCK-dependent; both effects were apparently secondary to kinase-mediated effects on cell volume changes. NHE1 in EATC is activated both by osmotic shrinkage and by the serine/threonine phosphatase inhibitor Calyculin A (CL-A). Both stimuli caused Rho kinase-dependent myosin II relocation to the cortical cytoplasm, but in contrast to the shrinkage-induced F-actin polymerization, CL-A treatment elicited a slight F-actin depolymerization. Moreover, Rho kinase inhibition did not significantly affect NHE1 activation, neither by shrinkage nor by CL-A. Implications for the possible interrelationship between changes in F-actin and myosin II, protein phosphorylation, and cell volume regulation are discussed.