The Arthur and Sonia Labatt Brain Tumour Research Centre, Division of Neurosurgery, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada.
Brain Pathol. 2010 Jan;20(1):190-9. doi: 10.1111/j.1750-3639.2008.00261.x. Epub 2009 Jan 15.
Fascin is a 55-kDa globular protein that functions to organize filamentous-actin into parallel bundles. A role for fascin in cell migration has led to its study in many tumor types. In this report, we investigate fascin in astrocytomas. We show that fascin is expressed in astrocytes and in a panel of human astrocytoma cell lines. Immunofluorescence analysis demonstrates that fascin and the intermediate filament protein, glial fibrillary acidic protein (GFAP), are both expressed in the perinuclear region and within cytoplasmic processes of astrocytes and astrocytoma cells. Amino acid residues within the NH2 terminus of GFAP can undergo phosphorylation; these modifications regulate intermediate filament disassembly and occur during cytokinesis. We show that fascin and specific phosphorylated species of GFAP colocalize within dividing cells. Finally, we demonstrate that fascin co-immunoprecipitates with GFAP and that immunocomplex formation is preferential for GFAP phosphorylated at serine residues 8 and 13. These data show that fascin and GFAP are immunolocalized regionally within cells and tumors of astrocytic origin and suggest that their binding may occur during dynamic reorganization of intermediate filaments.
Fascin 是一种 55kDa 的球形蛋白，其功能是将丝状肌动蛋白组织成平行束。 fascin 在细胞迁移中的作用使其成为许多肿瘤类型的研究对象。在本报告中，我们研究了星形细胞瘤中的 fascin。我们表明 fascin 在星形胶质细胞和一组人类星形细胞瘤细胞系中表达。免疫荧光分析表明 fascin 和中间丝蛋白胶质纤维酸性蛋白 (GFAP) 均在星形胶质细胞和星形细胞瘤细胞的核周区域和细胞质突起中表达。GFAP NH2 末端的氨基酸残基可以发生磷酸化；这些修饰调节中间丝的解体，并在有丝分裂过程中发生。我们表明 fascin 和特定的磷酸化 GFAP 物种在分裂细胞中共定位。最后，我们证明 fascin 与 GFAP 共免疫沉淀，并且免疫复合物的形成优先发生在丝氨酸残基 8 和 13 磷酸化的 GFAP 上。这些数据表明 fascin 和 GFAP 在星形胶质细胞来源的细胞和肿瘤中局部免疫定位，并表明它们的结合可能发生在中间丝的动态重排过程中。
