Phosphorylation of paxillin by p38MAPK is involved in the neurite extension of PC-12 cells.
Phosphorylation of paxillin by p38MAPK is involved in the neurite extension of PC-12 cells.
复制标题
p38mapk对帕西林的磷酸化参与PC-12细胞的神经突延伸。
DOI：
10.1083/jcb.200307081
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发表时间：
2004-02-16
期刊：
影响因子：
--
通讯作者：
Jacobson K
中科院分区：
文献类型：
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作者：
Huang C;Borchers CH;Schaller MD;Jacobson K
细胞粘附在神经突起延伸中起重要作用。桩蛋白是一种参与粘着斑动力学的粘着斑适配蛋白，已被证明是神经突生长所必需的。然而，桩蛋白调节神经突生长的分子机制尚不清楚。在这里，我们表明，桩蛋白磷酸化p38 MAPK在体外和神经生长因子（NGF）诱导的PC-12细胞。通过磷酸肽图谱和质谱分析，确定Ser 85（Ser 83为内源性桩蛋白）是主要的磷酸化位点之一。此外，桩蛋白的Ser 85 → Ala突变体（paxS 85 A）的表达显著抑制NGF诱导的PC-12细胞的神经突延伸，而野生型（wt）桩蛋白的表达不影响神经突生长。进一步的实验表明，表达paxS 85 A的细胞表现出小的、成簇的局灶性粘附，这在表达wt桩蛋白的细胞中通常看不到。尽管wt桩蛋白和paxS 85 A具有相同的结合黏着斑蛋白和粘着斑激酶的能力，但wt桩蛋白比paxS 85 A更有效地与Pyk 2缔合。因此，桩蛋白的磷酸化参与了NGF诱导的PC-12细胞的轴突延伸，可能是通过调节粘着斑组织。
Cell adhesions play an important role in neurite extension. Paxillin, a focal adhesion adaptor protein involved in focal adhesion dynamics, has been demonstrated to be required for neurite outgrowth. However, the molecular mechanism by which paxillin regulates neurite outgrowth is unknown. Here, we show that paxillin is phosphorylated by p38MAPK in vitro and in nerve growth factor (NGF)–induced PC-12 cells. Ser 85 (Ser 83 for endogenous paxillin) is identified as one of major phosphorylation sites by phosphopeptide mapping and mass spectrometry. Moreover, expression of the Ser 85 → Ala mutant of paxillin (paxS85A) significantly inhibits NGF-induced neurite extension of PC-12 cells, whereas expression of wild-type (wt) paxillin does not influence neurite outgrowth. Further experiments indicate that cells expressing paxS85A exhibit small, clustered focal adhesions which are not normally seen in cells expressing wt paxillin. Although wt paxillin and paxS85A have the same ability to bind vinculin and focal adhesion kinase, wt paxillin more efficiently associates with Pyk2 than paxS85A. Thus, phosphorylation of paxillin is involved in NGF-induced neurite extension of PC-12 cells, probably through regulating focal adhesion organization.