PhosphoMARCKS drives motility of mouse melanoma cells.
PhosphoMARCKS drives motility of mouse melanoma cells.
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DOI：
10.1016/j.cellsig.2010.03.003
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发表时间：
2010-07
影响因子：
4.8
通讯作者：
Rotenberg SA
中科院分区：
文献类型：
--
作者：
Chen X;Rotenberg SA
肉豆蔻酰化的富含丙氨酸的C-激酶底物(MARCK)被蛋白激酶Cα(PKCα)磷酸化，从而触发其从质膜/细胞骨架释放到细胞质中，从而促进肌动蛋白在迁移过程中的重组。这项研究表明，一旦释放到细胞质中，磷酸MARCKS直接促进黑色素瘤细胞的运动。侵袭性的B16F10小鼠黑色素瘤细胞表达高水平的磷酸化Marcks，而在运动性较弱的B16F1细胞中检测不到。在冈田酸(OA)(一种蛋白磷酸酶抑制剂)处理后，F1细胞表现出显著的磷酸MARCKS增加，并伴随着运动能力增加五倍。在OA添加之前，Marcks的表达被Marcks特异的shRNA敲除，从而表明Marcks是运动途径的主要组成部分，从而显著降低了Marcks的磷酸化和运动性。用PKC抑制剂(Calphostin C)观察到OA处理的细胞的运动性和磷酸化MARCKS水平降低，这表明PKC主动磷酸化F1细胞中的Marcks，但这一反应可被蛋白磷酸酶有效地抑制。Marcks-gfp的一个假磷酸化突变体进一步证实了磷酸化MARCKS对运动性的机制意义，其中Asp残基取代了已知被PKCα磷酸化的Ser残基。该突变体定位于细胞质，并在F1细胞中产生三倍以上的运动能力。MARCKS突变体的表达定位于细胞质，可阻断40-50%的油酸刺激的F1细胞和固有运动的F10细胞的运动。这些结果表明，磷酸MARCKS有助于黑色素瘤细胞的转移潜能，并揭示了这种细胞质磷酸蛋白以前未见文献报道的信号作用。
Phosphorylation of Myristoylated Alanine-rich C-Kinase Substrate (MARCKS) by protein kinase Cα(PKCα) is known to trigger its release from the plasma membrane/cytoskeleton into the cytoplasm, thereby promoting actin reorganization during migration. This study shows that once released into the cytoplasm, phosphoMARCKS directly promotes motility of melanoma cells. Aggressively motile B16 F10 mouse melanoma cells express high levels of phospho-MARCKS, whereas in weakly motile B16 F1 cells it is undetectable. Following treatment with okadaic acid (OA) (a protein phosphatase inhibitor), F1 cells exhibited a dramatic increase in phosphoMARCKS and was co-incident with a five-fold increase in motility. Both MARCKS phosphorylation and motility were substantially decreased when prior to OA addition, MARCKS expression was knocked out by a MARCKS-specific shRNA, thereby implicating MARCKS as a major component of the motility pathway. Decreased motility and phosphoMARCKS levels in OA-treated cells was observed with a PKC inhibitor (calphostin C), thus indicating that PKC actively phosphorylates MARCKS in F1 cells but that this reaction is efficiently suppressed by protein phosphatases. The mechanistic significance of phosphoMARCKS to motility was further established with a pseudo-phosphorylated mutant of MARCKS-GFP in which Asp residues replaced Ser residues known to be phosphorylated by PKCα. This mutant localized to the cytoplasm and engendered three-fold higher motility in F1 cells. Expression of an unmyristoylated, phosphorylation-resistant MARCKS mutant that localized to the cytoplasm, blocked motility by 40–50% of both OA-stimulated F1 cells and intrinsically motile F10 cells. These results demonstrate that phosphoMARCKS contributes to the metastatic potential of melanoma cells, and reveal a previously undocumented signaling role for this cytoplasmic phospho-protein.
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影响因子：
4.8
作者：
Garcia-Bermejo, ML;Leskow, FC;Kazanietz, MG
通讯作者：
Kazanietz, MG
影响因子：
4
作者：
PREZIOSO, JA;WANG, N;GORELIK, E
通讯作者：
GORELIK, E
DOI：
10.1016/0006-291x(91)90922-t
发表时间：
1991-04-15
影响因子：
3.1
作者：
BRUNS, RF;MILLER, FD;NAKANO, H
通讯作者：
NAKANO, H
影响因子：
4.8
作者：
Abeyweera, Thushara P.;Chen, Xiangyu;Rotenberg, Susan A.
通讯作者：
Rotenberg, Susan A.
影响因子：
4
作者：
LaPorta, CAM;Comolli, R
通讯作者：
Comolli, R