Research Conserved function of the HAUS6 calponin homology domain in anchoring augmin for microtubule branching
Structural insights into augmin-driven microtubule orientation during cell division
Accurate microtubule organization in space and time is crucial for cell division. By recruiting the microtubule nucleator γ-tubulin ring complex to pre-existing microtubules, the augmin complex amplifies microtubules in a predefined orientation and thereby plays an essential role in the assembly of a functional mitotic spindle.
In a collaborative effort, the groups of Stefan Pfeffer and Elmar Schiebel (ZMBH, Heidelberg), Sebastian Eustermann (EMBL Heidelberg), Sylvia Erhardt (KIT, Karlsruhe), and Fabio Lolicato (BZH, Heidelberg) followed a structure-guided integrative approach to identify and functionally characterize augmin’s microtubule-binding unit across species. Their work revealed that the conserved calponin homology domain of the augmin subunit HAUS6 anchors augmin on the microtubule surface and thereby establishes the orientation of newly nucleated microtubules. These insights substantially advance structural and mechanistic understanding of how augmin directs microtubule branching and contributes to the spatial organization of the mitotic spindle.
