TPX2
TPX2 (TPX2 microtubule nucleation factor, also known as targeting protein for Xklp2, p100, DIL-2 and HCA519) is a spindle assembly factor required for the normal assembly of mitotic spindles. It activates Aurora kinase A and promotes local microtubule nucleation. Browse Assay Genie's current range of TPX2 research reagents below, or read on for the biology behind the target.
TPX2 is a spindle assembly factor needed for the normal assembly of mitotic spindles. It is required for chromatin- and/or kinetochore-dependent microtubule nucleation, and for normal microtubule assembly during apoptosis. NCBI Gene annotation also links it to microtubule cytoskeleton organisation and to negative regulation of microtubule depolymerisation.
A central role of TPX2 is the control of Aurora kinase A (AURKA). TPX2 mediates the localisation of AURKA to spindle microtubules. It activates AURKA by promoting autophosphorylation at Thr-288 and protects that residue against dephosphorylation. Consistent with this, the TPX2 protein is annotated with importin-alpha family protein binding, protein kinase binding and protein serine/threonine kinase activator activity.
TPX2 activity is regulated by importin-alpha. Binding to importin-alpha inactivates TPX2. At the onset of mitosis, GOLGA2 interacts with importin-alpha and liberates TPX2, which can then activate AURKA and stimulate local microtubule nucleation. TPX2 is located in the nucleus and nucleoplasm, and at the spindle, spindle pole and intercellular bridge. It belongs to the TPX2 family. The TPX2 gene was previously listed as C20orf2 and C20orf1, and the protein also carries the aliases FLS353 and DIL-2. A mouse ortholog, Tpx2, is recognised.
Its name derives from the Xenopus protein targeting protein for Xklp2, reflected in earlier HGNC names such as TPX2, microtubule-associated, homolog (Xenopus laevis).
TPX2 is required for normal assembly of mitotic spindles, making it a core factor for studying how spindles form.
TPX2 supports chromatin- and kinetochore-dependent microtubule nucleation and stimulates local nucleation once released from importin-alpha.
TPX2 localises AURKA to spindle microtubules and promotes its Thr-288 autophosphorylation, a useful system for kinase activation studies.
Inactivation of TPX2 by importin-alpha, and its release via GOLGA2 at mitotic onset, offers a model of spatial control in mitosis.
TPX2 is a spindle assembly factor required for normal assembly of mitotic spindles. It mediates AURKA localisation to spindle microtubules, activates AURKA by promoting Thr-288 autophosphorylation, and supports chromatin- and kinetochore-dependent microtubule nucleation. It is also needed for microtubule assembly during apoptosis.
TPX2 stands for TPX2 microtubule nucleation factor, and UniProt lists it as targeting protein for Xklp2. Aliases include p100, DIL-2, HCA519 and FLS353. Earlier symbols were C20orf2 and C20orf1, from chromosome 20 open reading frame 1.
Binding to importin-alpha inactivates TPX2. At mitotic onset, GOLGA2 interacts with importin-alpha, freeing TPX2 to activate AURKA. A mouse ortholog, Tpx2, exists, and the name derives from the Xenopus protein; check the datasheet of any product for its validated reactivity.
Aurora kinase A, importin-alpha, golgin and other mitotic spindle regulators with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q9ULW0; product specifications from Assay Genie datasheets.