GAS2L1 Is a Centriole-Associated Protein Required for Centrosome Dynamics and Disjunction

Publication date: Available online 22 December 2016
Source:Developmental Cell
Author(s): Franco K.C. Au, Yue Jia, Kai Jiang, Ilya Grigoriev, Bill K.T. Hau, Yuehong Shen, Shengwang Du, Anna Akhmanova, Robert Z. Qi
Mitotic spindle formation and chromosome segregation require timely separation of the two duplicated centrosomes, and this process is initiated in late G2 by centrosome disjunction. Here we report that GAS2L1, a microtubule- and actin-binding protein, associates with the proximal end of mature centrioles and participates in centriole dynamics and centrosome disjunction. GAS2L1 attaches microtubules and actin to centrosomes, and the loss of GAS2L1 inhibits centrosome disjunction in G2 and centrosome splitting induced by depletion of the centrosome linker rootletin. Conversely, GAS2L1 overexpression induces premature centrosome separation, and this activity requires GAS2L1 association with actin, microtubules, and the microtubule end-binding proteins. The centrosome-splitting effect of GAS2L1 is counterbalanced by rootletin, reflecting the opposing actions of GAS2L1 and the centrosome linker. Our work reveals a GAS2L1-mediated centriole-tethering mechanism of microtubules and actin, which provide the forces required for centrosome dynamics and separation.

Teaser

Centrosome separation is crucial for bipolar spindle assembly and requires dissolution of the centrosomal linker, as well as actin and microtubule-based forces. Au, Jia et al. now show that GAS2L1, a centriole-localizing protein, links centrosomes to both microtubules and actin, thus promoting centrosome separation upon linker disassembly.


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