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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, RESULTS. Meshes: Animals, Aurora Kinases, Chromosome Segregation, HeLa Cells, Humans, Microtubule-Associated Proteins, Microtubules, Multiprotein Complexes, Neoplasm Proteins, Protein-Serine-Threonine Kinases, Spindle Apparatus, Xenopus, Xenopus Proteins, ran GTP-Binding Protein.
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Is hURP part of a Ran-dependent complex involved in spindle formation? Context: GTP-loaded Ran induces the assembly of microtubules into aster-like and spindle-like structures in Xenopus egg extract. The microtubule-associated protein (MAP), TPX2, can mediate Ran's role in aster formation, but factors responsible for the transition from aster-like to spindle-like structures have not been described. Here we identify a complex that is required for the conversion of aster-like to spindle-like structures. The complex consists of two characterized MAPs (TPX2, XMAP215), a plus end-directed motor (Eg5), a mitotic kinase (Aurora A), and HURP, a protein associated with hepatocellular carcinoma. Formation and function of the complex is dependent on Aurora A activity. HURP protein was further characterized and shown to bind microtubules and affect their organization both in vitro and in vivo. In egg extract, anti-HURP antibodies disrupt the formation of both Ran-dependent and chromatin and centrosome-induced spindles. HURP is also required for the proper formation and function of mitotic spindles in HeLa cells.
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HURP is a new and essential component of the mitotic apparatus. HURP acts as part of a multicomponent complex that affects the growth or stability of spindle MTs and is required for spindle MT organization. Final Decision: yes