Human centromeres are defined by alpha satellite DNA arrays that are distinct and chromosome specific. Most human chromosomes contain multiple alpha satellite arrays that are competent for centromere assembly. Here, we show that human centromeres are defined by chromosome-specific RNAs linked to underlying organization of distinct alpha satellite arrays. Active and inactive arrays on the same chromosome produce discrete sets of transcripts in cis. Non-coding RNAs produced from active arrays are complexed with CENP-A and CENP-C, while inactive-array transcripts associate with CENP-B and are generally less stable. Loss of CENP-A does not affect transcript abundance or stability. However, depletion of array-specific RNAs reduces CENP-A and CENP-C at the targeted centromere via faulty CENP-A loading, arresting cells before mitosis. This work shows that each human alpha satellite array produces a unique set of non-coding transcripts, and RNAs present at active centromeres are necessary for kinetochore assembly and cell-cycle progression.

人类着丝粒由不同且染色体特异性的 α 卫星 DNA 阵列定义。大多数人类染色体包含多个能够进行着丝粒组装的α卫星阵列。在这里，我们表明人类着丝粒是由与不同 α 卫星阵列的基本组织相关的染色体特异性 RNA 定义的。同一染色体上的活性和非活性阵列在顺式中产生离散的转录集. 由活性阵列产生的非编码 RNA 与 CENP-A 和 CENP-C 复合，而非活性阵列转录本与 CENP-B 相关联并且通常不太稳定。CENP-A 的缺失不会影响转录本丰度或稳定性。然而，阵列特异性 RNA 的消耗会通过错误的 CENP-A 加载减少目标着丝粒处的 CENP-A 和 CENP-C，从而在有丝分裂前阻止细胞。这项工作表明，每个人类 α 卫星阵列都会产生一组独特的非编码转录本，而活跃着丝粒中存在的 RNA 对于着丝粒组装和细胞周期进程是必需的。