Functional Structure of Centromere/Kinetochore Domain of Mammalian Chromosomes

本研究的目的是通过鉴定哺乳动物染色体着丝粒/着丝粒功能结构的DNA序列和蛋白质因子，获得了解染色体分离调控机制所需的基本信息。获得了以下信息1.高度重复的α-卫星DNA(α-卫星DNA)定位于着丝粒区域。用抗着丝点抗体在自身免疫病患者血清中检测到CENP-A(17kD)、CENP-B(80kD)和CENP-C(140kD)三种抗原。这些抗原与人类染色体的着丝粒结构域特异相关。CENP-B与甲型DNA在甲型DNA的17bp基序(CENP-B盒)上形成复合体。CENP-B盒序列存在于所有人类染色体的着丝粒区域，包括Y染色体，其中似乎只有很少的量存在。在小鼠着丝粒卫星DNA中也发现了CENP-B盒。着丝粒抗原与CENP-B盒形成复合体，存在于小鼠、印度猴和猴的核提取液中。αDNA与CENP-B形成的复合体由两个DNA分子和可能的两个CENP-B分子组成，因此CENP-B/CENP-B盒相互作用广泛存在于哺乳动物的染色体中，这种相互作用似乎在着丝粒DNA的高级形成中起作用。

The purpose of this research is to obtain the basic information reguired to understand the regulation mechanism of chromosome segregation through the identification of DNA sequence and protein factors responsible for the functional structure of centromere/kinetochore of mammalian chromosomes. Following information was obtained.1. Highly repetitive alpha-satellite DNA (alphoid DNA) is localized at centromere domain.2. Three antigens {CENP-A (17 kD), CENP-B (80 kD) and CENP-C (140 kD)} are detected with anticentromere antibodies in sera from autoimmune patients. These antigens are specifically associated with centromere domain of human chromosomes.3. CENP-B and alphoid DNA form a complex at the 17 bp motif (CENP-B box) in alphoid DNA.4. CENP-B box sequences are detected at centromere domain of all human chromosomes, including Y-chromosome in which only very small amount seems to be present. The CENP-B box is also found in centromeric satellite DNA of mouse.5. Centromere antigens which form a complex with the CENP-B box are found in nuclear extracts of mouse, Indian muntjac and monkey cells.6. A complex formed between alphoid DNA and CENP-B consists of two DNA molecules and probably two CENP-B molecules.Thus, CENP-B/CENP-B box interaction is widely found in mammalian chromosomes and this interaction seems to play a role in higher order formation of centromeric alphoid DNA.