The Btk29A Tyrosine Kinase Gene of Drosophila

果蝇 Btk29A 酪氨酸激酶基因

• 批准号: 9730039
• 负责人: Steven Beckendorf
• 金额: $ 30万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9730039&HistoricalAwards=false
• 关键词: Btk29A; Tyrosine; Kinase; Gene; Drosophila

The Btk29A kinase is the only Drosophila member of a subfamily of tyrosine kinases that includes the mammalian kinases Btk, Itk and Tec. The mammalian proteins are required for hematopoiesis and the immune response, and are activated in response to signaling from the B-cell and T-cell receptors. Although Btk29A is expressed in a dynamic and complex pattern that includes the blood cells, there has been little investigation of the requirements for Btk29A in Drosophila. The PI recently identified Btk29A mutants and was able to show that it is essential for embryogenesis, for formation of bristles in the eye, and for the late stages of oogenesis. In addition, the PI has shown a genetic interaction between Btk29A and Src64B, which encodes a Src-family tyrosine kinase closely related to those that activate Btk, Itk and Tec. The PI now plans to examine this interaction more closely and search for additional genes in the Btk29A pathway. To get a more complete idea of the roles of Btk29A in embryogenesis, eye development, and oogenesis, the PI will isolate Btk29A null mutants and construct a Btk29A transposon that rescues the mutant phenotypes. Both Btk29A and Src64B are required for ring canal growth in developing egg chambers and interact genetically to give a more extreme phenotype. The PI will test the effects of these mutants on phosphotyrosine incorporation into the ring canals and will test whether the two kinases interact directly. The PI has recently shown that ring canals carry phosphothreonine as well as phosphotyrosine and that the phosphothreonine is also dependent on Btk29A. The PI plans to test whether the phosphotyrosine signal is transduced to phosphothreonine via the Ras or Rho families of small GTPases. Btk29A and Src64B are also required for dorsoventral patterning of the follicle cells. The PI plans to test whether they work in the Egfr-Ras pathway in these cells. In the absence of Btk29A the interommatidial bristles of the eye are truncated. The PI plans to compare growth of normal and mutant bristles using labeled phalloidin and antibodies to Btk29A, phosphotyrosine and phosphothreonine. Then the PI will use a sensitized screen to isolate mutations that enhance or suppress the bristle phenotype. Among these the PI hopes to find mutations in new members of Btk29A signaling pathways.

Btk29A 激酶是酪氨酸激酶亚家族中唯一的果蝇成员，该亚家族包括哺乳动物激酶 Btk、Itk 和 Tec。哺乳动物蛋白质是造血和免疫反应所必需的，并响应来自 B 细胞和 T 细胞受体的信号而被激活。尽管 Btk29A 以包括血细胞在内的动态且复杂的模式表达，但对果蝇中 Btk29A 的需求的研究很少。 PI 最近鉴定了 Btk29A 突变体，并证明它对于胚胎发生、眼睛刚毛的形成以及卵子发生的后期至关重要。此外，PI还显示了Btk29A和Src64B之间的遗传相互作用，Src64B编码与激活Btk、Itk和Tec的酪氨酸激酶密切相关的Src家族酪氨酸激酶。 PI 现在计划更仔细地研究这种相互作用，并寻找 Btk29A 通路中的其他基因。为了更全面地了解 Btk29A 在胚胎发生、眼睛发育和卵子发生中的作用，PI 将分离 Btk29A 无效突变体并构建拯救突变表型的 Btk29A 转座子。 Btk29A 和 Src64B 都是发育中的卵室中环管生长所必需的，并且在遗传上相互作用以产生更极端的表型。 PI 将测试这些突变体对磷酸酪氨酸掺入环管的影响，并将测试这两种激酶是否直接相互作用。 PI 最近表明，环管携带磷酸苏氨酸和磷酸酪氨酸，并且磷酸苏氨酸也依赖于 Btk29A。 PI 计划测试磷酸酪氨酸信号是否通过小 GTP 酶的 Ras 或 Rho 家族转导为磷酸苏氨酸。 Btk29A 和 Src64B 也是卵泡细胞背腹侧模式所必需的。 PI 计划测试它们是否在这些细胞的 Egfr-Ras 通路中发挥作用。 在缺乏 Btk29A 的情况下，眼睛的小间刚毛被截断。 PI 计划使用标记的鬼笔环肽和 Btk29A、磷酸酪氨酸和磷酸苏氨酸抗体来比较正常和突变刷毛的生长情况。然后，PI 将使用敏化筛选来分离增强或抑制鬃毛表型的突变。其中，PI 希望找到 Btk29A 信号通路新成员的突变。