Centriole amplification in multiciliated cells occurs in a pseudo-cell cycle regulated process that typically utilizes a poorly characterized molecularly dense structure called the deuterosome. We identified the centrosomal protein Cep70 as a novel deuterosome-associated protein that forms a complex with other deuterosome proteins, CCDC78 and Deup1. Cep70 dynamically associates with deuterosomes during centriole amplification in the ciliated epithelia of Xenopus embryos. Cep70 is not found in nascent deuterosomes prior to amplification. However, it becomes localized at deuterosomes at the onset of centriole biogenesis and remains there after the completion of centriole amplification. Deuterosome localization requires a conserved C-terminal “Cep70” motif. Depletion of Cep70 using morpholino oligos or CRISPR/Cas9 editing in F0 embryos leads to a severe decrease in centriole formation in both endogenous MCCs, as well as ectopically induced MCCs. Consistent with a decrease in centrioles, endogenous MCCs have defects in the process of radial intercalation. We propose that Cep70 represents a novel regulator of centriole biogenesis in MCCs.

多纤毛细胞中的中心粒扩增发生在假细胞周期调节过程中，该过程通常利用称为氘核体的特征不佳的分子致密结构。我们将中心体蛋白 Cep70 鉴定为一种新的氘核相关蛋白，它与其他氘核蛋白 CCDC78 和 Deup1 形成复合物。Cep70 在爪蟾纤毛上皮细胞中心粒扩增过程中与氘核体动态结合胚胎。在扩增之前，在新生的氘核体中未发现 Cep70。然而，它在中心粒生物发生开始时定位于氘核体，并在中心粒扩增完成后保留在那里。氘核定位需要一个保守的 C 末端“Cep70”基序。在 F0 胚胎中使用吗啉代寡核苷酸或 CRISPR/Cas9 编辑去除 Cep70 会导致内源性 MCC 以及异位诱导的 MCC 中的中心粒形成严重减少。与中心粒减少一致，内源性MCC在径向插入过程中存在缺陷。我们建议 Cep70 代表 MCC 中中心粒生物发生的新调节剂。