Cortés Joel Cerna, Montalvo Eliud Alfredo Garcia, Muñiz Jesús, Mornet Dominique, Garrido Efrain, Centeno Federico, Cisneros Bulmaro
University Center of Biomedical Research, Universidad de Colima, Avenida 25 de Julio 965 Col. Villa San Sebastián, C.P. 28045, Colima, Colima, Mexico.
Neurochem Res. 2009 Mar;34(3):438-44. doi: 10.1007/s11064-008-9802-x. Epub 2008 Aug 2.
Previously, it was shown that Dp71f binds to the beta1-integrin adhesion complex to modulate PC12 cell adhesion. The absence of Dp71f led to a failure in the beta1-integrin adhesion complex formation. One of the structural proteins which links the beta1-integrin cytoplasmic domain to the actin cytoskeleton is ILK. GSK3-beta is an ILK substrate and the carboxi-terminal region of dystrophin 427 is a substrate for hierarchical phosphorylation by GSK3-beta. Dp71f contains the carboxi-terminal domain present in dystrophin 427. By using co-immunoprecipitation assays, in the present work it is demonstrated that in the neuronal PC12 cell line an interaction between Dp71f and GSK3-beta occurs. This interaction was corroborated by in vitro pulldown assays. We show that GSK3-beta is recruited to the beta1-integrin complex and that a reduced expression of Dp71f induces a reduced GSK3-beta recruitment to the beta1-integrin complex. In addition, the present work establishes that adhesion of PC12 cells to laminin does not influence the phosphorylation status of Dp71f.
先前的研究表明，Dp71f与β1整合素黏附复合体结合，以调节PC12细胞的黏附。Dp71f的缺失导致β1整合素黏附复合体形成失败。将β1整合素胞质结构域与肌动蛋白细胞骨架连接起来的结构蛋白之一是整合素连接激酶（ILK）。糖原合成酶激酶3β（GSK3-β）是ILK的底物，肌营养不良蛋白427的羧基末端区域是GSK3-β进行分级磷酸化的底物。Dp71f包含肌营养不良蛋白427中存在的羧基末端结构域。通过免疫共沉淀实验，在本研究中证明，在神经元PC12细胞系中，Dp71f与GSK3-β之间存在相互作用。这种相互作用通过体外下拉实验得到了证实。我们发现GSK3-β被招募到β1整合素复合体，并且Dp71f表达的降低导致GSK3-β向β1整合素复合体的招募减少。此外，本研究还确定PC12细胞与层粘连蛋白的黏附不会影响Dp71f的磷酸化状态。
