HAUS2

HAUS2 is a subunit of the Augmin/HAUS complex that supports microtubule nucleation along the mitotic spindle and maintains centrosome integrity in dividing cells (PMID:28596487). Combinatorial knockdown of HAUS2 together with the Augmin subunit HAUS5 in neural progenitor cells causes centrosome fragmentation and cell death, demonstrating that HAUS2 functionally contributes to essential Augmin/HAUS complex activity required for centrosome integrity and viability (PMID:28596487). Beyond this genetic epistasis, no further mechanistic detail — including biochemical reconstitution, structural assembly within the complex, or direct microtubule-binding activity of HAUS2 itself — has been characterized in the available corpus.

1. 2017 Medium

   Established that HAUS2 is not merely an annotated complex member but functionally contributes to Augmin/HAUS activity required for centrosome integrity and cell survival.

   Evidence Combinatorial siRNA knockdown of HAUS2 with HAUS5 in neural progenitor cells, scored for centrosome fragmentation and viability

   PMID:28596487

   Open questions at the time

   • No in vitro reconstitution or structural data defining HAUS2's role within the complex
   • Single-lab study relying on combinatorial knockdown rather than isolated HAUS2 loss
   • Direct molecular activity of HAUS2 (e.g., microtubule binding or nucleation contribution) not measured

• How HAUS2 contributes biochemically to Augmin-dependent microtubule nucleation and what its direct binding partners and structural position within the complex are remain unresolved.
• No structural model of HAUS2 within the Augmin/HAUS complex
• No reconstituted assay isolating HAUS2's molecular function
• No direct demonstration of HAUS2-microtubule interaction