一直以来，我们着眼于有丝分裂、染色体不稳定性和癌症中着丝粒-动粒蛋白的研究。现在我们将通过研究干细胞试图解决的癌症和神经系统疾病的问题。前期我们已报道了CENP-A泛素化的必要功能是决定着丝粒身份。目前的发现已经揭示了无膜细胞器和不均等细胞分裂在发育、分化和癌症中的调控和作用。为探索这一问题，我们将依据以下三个目标从分子到个体水平了解染色体分离的表观遗传学调控。.【目标1】我们将带着全新的假设进一步深入研究人类CENP-A泛素化的分子机制。.【目标2】我们将在细胞和模式动物（斑马鱼）水平对异常的CENP-A分子伴侣，DAXX和其互作因子TSG101进行功能分析，以揭示CENP-A和/或MAD2过表达癌症的相关机制。.【目标3】我们将在模式动物（斑马鱼和小鼠）中研究CENP-A泛素化信号通路上游成分SUGT1的生理功能，以揭示神经系统失调的机制。

It is the ultimate goal of life science to solve both cancer and dementia, and now stem cell research is remarkably developing. However, number of the research carrying out from the perspective to solve both cancer and dementia is surprisingly small, and research of the cell division focusing on stem cells is extremely delayed..During cell division, proper chromosomes segregation must be achieved otherwise it can result in unequal distribution of chromosomes to daughter cells. Spindle microtubules must attach to a single region of each chromosome, termed the “centromere,” in most eukaryotes. The kinetochore is a complex of proteins that is located at the centromere. Defects in the centromere-kinetochore function as well as the spindle check point function, lead to to aneuploidy and cancer, and are often associated with a poor prognosis. Therefore, it is highly important to study the temporal-special regulation and the structure of centromere and kinetochore protein(s) to understand chromosome instability (CIN) and cancer progression. .Mitotic regulators of our interests include but not limited to centromere-kinetochore proteins, microtubule binding proteins, mitotic enzymes, and chaperons and co-chaperons that facilitate proper chromosome segregation. Importantly, the functions of mitotic regulators are neither limited to the roles of cell division, and often extended to the roles of other cell cycle stages such as G1(G0)/S phases in post mitotic neurons. Therefore, studying the cell cycle-specific functions of mitotic regulators involved in cancer and nervous system disorder would be expected for future research..The key question is how the chromosomal location and function of a centromere (i.e., centromere identity) are determined and thus participate in accurate chromosome segregation. In most species, centromere identity relies not on defined DNA sequence, but on the presence of a special nucleosome that contains a specific histone-like protein called CENP-A. CENP-A is proposed to be the non-DNA indicator (epigenetic mark) of centromere identity. CENP-A is at the top of a hierarchy of the pathway that determines the assembly of kinetochore components, and how CENP-A defines the position of the centromere in humans is fundamental question. We have previously reported that the CUL4A-RBX1-COPS8 E3 ligase is required for CENP-A ubiquitylation on lysine 124 (K124) and centromere localization. Furthermore, we showed that pre-existing ubiquitylated CENP-A is necessary for the centromere recruitment of newly synthesized CENP-A and provide the model that CENP-A ubiquitylation is inherited
through dimerization between cell divisions. .Recent discoveries have shed light on the molecular properties, formation, regulation, and function of membraneless organelles, and regulation of asymmetric cell divisions in development, differentiation and cancer. Exploring these topics, we will understand epigenetic regulations of chromosome segregation from molecule to body level following 3 specific aims. .(Specific aim 1) We will further perform in-depth study of the molecular mechanism of human CENP-A ubiquitylation. .(Specific aim 2) We will perform functional analysis of ectopic CENP-A chaperone, DAXX, and its interactor TSG101 in cell and model animal (zebrafish), that would directly link to the mechanism of CENP-A and/or MAD2-overexpressing cancer. .(Specific aim 3) We will study physiological function of SUGT1, a component of upstream signaling of CENP-A deposition into centromeric nucleosome, in model animals (zebrafish and mouse). This study will directly lead to the elucidation of physiological functions of SUGT1 especially in cancer and nervous system disorder.