Salgia R, Avraham S, Pisick E, Li J L, Raja S, Greenfield E A, Sattler M, Avraham H, Griffin J D
Division of Hematologic Malignancies, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115, USA.
J Biol Chem. 1996 Dec 6;271(49):31222-6. doi: 10.1074/jbc.271.49.31222.
Related adhesion focal tyrosine kinase (RAFTK), also known as proline-rich tyrosine kinase 2 and cellular adhesion kinase beta, has been recently cloned and characterized as a member of the focal adhesion kinase (FAK) subfamily. RAFTK has an overall 48% amino acid homology to p125(FAK) and contains a kinase domain but lacks a transmembrane region, myristylation sites, and Src homology region 2 and 3 domains. By Northern blot analysis, RAFTK is expressed in myeloid, lymphoid, and megakaryocytic hematopoietic cells. Like p125(FAK), we found that RAFTK interacts with the focal adhesion protein paxillin. In the lymphoid cell line BaF3 and the myeloid cell line 32Dcl3, RAFTK coprecipitates with paxillin. Using in vitro binding assays, RAFTK and paxillin were shown to bind directly, through a segment of paxillin that required amino acids 100-227 and a domain in the C terminus of RAFTK. In vitro, RAFTK could phosphorylate paxillin on tyrosine residues. These results suggest that RAFTK, as well as p125(FAK), may be important in phosphotyrosine-signaling events within the focal adhesion.
相关黏附斑酪氨酸激酶（RAFTK），也被称为富含脯氨酸的酪氨酸激酶2和细胞黏附激酶β，最近已被克隆，并被鉴定为黏附斑激酶（FAK）亚家族的成员。RAFTK与p125（FAK）的氨基酸总体同源性为48%，包含一个激酶结构域，但缺乏跨膜区域、肉豆蔻酰化位点以及Src同源区域2和3结构域。通过Northern印迹分析，RAFTK在髓系、淋巴系和巨核系造血细胞中表达。与p125（FAK）一样，我们发现RAFTK与黏附斑蛋白桩蛋白相互作用。在淋巴样细胞系BaF3和髓样细胞系32Dcl3中，RAFTK与桩蛋白共沉淀。使用体外结合试验表明，RAFTK和桩蛋白通过桩蛋白中需要氨基酸100 - 227的一段序列以及RAFTK C末端的一个结构域直接结合。在体外，RAFTK可以使桩蛋白的酪氨酸残基磷酸化。这些结果表明，RAFTK以及p125（FAK）可能在黏附斑内的磷酸酪氨酸信号事件中起重要作用。
