Regulation of Hh/Ci signaling by Cos2 and its partners

描述(申请人提供)：我的实验室的长期目标是了解Hedgehog(HH)信号是如何传递的，以控制各种细胞行为。HH家族分泌蛋白控制着动物发育的许多方面。HH信号的故障与包括癌症在内的许多人类疾病有关。HH家族成员通过进化上保守但定义不明确的信号转导级联来发挥其生物学影响。HH信号转导的一个关键步骤是激活Cubitus interruptus(Ci)，它受含有激动素相关蛋白Costa2(Cos2)的大蛋白复合体的调节。我们开发了一种在体内检测Cos2相互作用蛋白的新方法，并鉴定了Cos2/Ci复合体的几个新组分。在这项拟议的研究中，我们将结合遗传、生化、细胞和药理学方法来研究Cos2及其相互作用蛋白调节Ci磷酸化、活性和亚细胞定位的机制。特别是，我们计划1)研究不同的Cos2复合体调控Ci核转位的机制；2)研究GSK3/Cos2相互作用在Ci磷酸化中的作用和调节；3)研究酪蛋白激酶I(CKI)在HH信号转导中的作用及其潜在机制；4)确定一个新的Cos2相互作用蛋白Koro的作用，并鉴定和表征其他调节Ci活性的Cos2相互作用蛋白。从拟议的研究中获得的知识将有助于阐明HH信号是如何被转导以控制细胞生长和模式的，并可能为HH信号活性的错误调节所引起的癌症的诊断和治疗干预提供新的途径。

DESCRIPTION (provided by applicant): The long-term goal of my laboratory is to understand how Hedgehog (Hh) signal is transduced to control a wild variety of cellular behaviors. Hh family of secreted proteins controls many aspects of animal development. Malfunction of Hh signaling has been linked to numerous human disorders including cancers. Hh family members exert their biological influence through an evolutionarily conserved, yet poorly defined signal transduction cascade. A critical step in Hh signal transduction is the activation of Cubitus interruptus (Ci), which is regulated by large protein complexes containing the kinesin-related protein Costal2 (Cos2). We have developed a novel method for detecting Cos2 interacting proteins in vivo and have identified several novel components of Cos2/Ci complexes. In the proposed study, we will use a combination of genetic, biochemical, cellular, and pharmacological approaches to investigate the mechanisms by which Cos2 and its interacting proteins regulate Ci phosphorylation, activity, and subcellular localization. In particular, we plan to 1) investigate the mechanism by which distinct Cos2 complexes regulate Ci nuclear translocation; 2) study the role and regulation of GSK3/Cos2 interaction in Ci phosphorylation; 3) investigate the role of casein kinase I (CKI) in Hh signaling and the underlying mechanism; 4) determine the role of a novel Cos2 interacting protein, Koro, and identify and characterize additional Cos2 interacting proteins that regulate Ci activity. Knowledge gained from the proposed study shall shed light into how Hh signal is transduced to control cell growth and patterning, and may provide new avenues for diagnosis and therapeutic intervention of cancers caused by mis-regulation of Hh signaling activity.