Human Microcephaly Protein <i>RTTN</i> Is Required for Proper Mitotic Progression and Correct Spindle Position

• Main Authors: En-Ju Chou, Tang K. Tang
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Cells
• Subjects: primary microcephaly; <i>MCPH</i>; centriole; centrosome; cell division; neural progenitors
• Online Access: https://www.mdpi.com/2073-4409/10/6/1441

Autosomal recessive primary microcephaly (<i>MCPH</i>) is a complex neurodevelopmental disorder characterized by a small brain size with mild to moderate intellectual disability. We previously demonstrated that human microcephaly <i>RTTN</i> played an important role in regulating centriole duplication during interphase, but the role of <i>RTTN</i> in mitosis is not fully understood. Here, we show that <i>RTTN</i> is required for normal mitotic progression and correct spindle position. The depletion of <i>RTTN</i> induces the dispersion of the pericentriolar protein γ-tubulin and multiple mitotic abnormalities, including monopolar, abnormal bipolar, and multipolar spindles. Importantly, the loss of <i>RTTN</i> altered NuMA/p150Glued congression to the spindle poles, perturbed NuMA cortical localization, and reduced the number and the length of astral microtubules. Together, our results provide a new insight into how <i>RTTN</i> functions in mitosis.