CKAP5

This gene encodes a cytoskeleton-associated protein which belongs to the TOG/XMAP215 family. The N-terminal half of this protein contains a microtubule-binding domain and the C-terminal half contains a KXGS motif for binding tubulin dimers. This protein has two distinct roles in spindle formation; it protects kinetochore microtubules from depolymerization and plays an essential role in centrosomal microtubule assembly. This protein may be necessary for the proper interaction of microtubules with the cell cortex for directional cell movement. It also plays a role in translation of the myelin basic protein (MBP) mRNA by interacting with heterogeneous nuclear ribonucleoprotein (hnRNP) A2, which associates with MBP. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Aug 2011]

Full Name

Cytoskeleton Associated Protein 5

Function

Binds to the plus end of microtubules and regulates microtubule dynamics and microtubule organization. Acts as processive microtubule polymerase. Promotes cytoplasmic microtubule nucleation and elongation. Plays a major role in organizing spindle poles. In spindle formation protects kinetochore microtubules from depolymerization by KIF2C and has an essential role in centrosomal microtubule assembly independently of KIF2C activity. Contributes to centrosome integrity. Acts as component of the TACC3/ch-TOG/clathrin complex proposed to contribute to stabilization of kinetochore fibers of the mitotic spindle by acting as inter-microtubule bridge. The TACC3/ch-TOG/clathrin complex is required for the maintenance of kinetochore fiber tension (PubMed:23532825).

Enhances the strength of NDC80 complex-mediated kinetochore-tip microtubule attachments (PubMed:27156448).

Biological Process

Cell division Source: UniProtKB-KW
Centrosome cycle Source: HGNC-UCL
Centrosome duplication Source: GO_Central
Ciliary basal body-plasma membrane docking Source: Reactome
Establishment or maintenance of microtubule cytoskeleton polarity Source: HGNC-UCL
G2/M transition of mitotic cell cycle Source: Reactome
Microtubule depolymerization Source: ARUK-UCL
Microtubule polymerization Source: GO_Central
Mitotic spindle organization Source: GO_Central
Positive regulation of microtubule nucleation Source: CACAO
Regulation of G2/M transition of mitotic cell cycle Source: Reactome
RNA transport Source: HGNC-UCL
Spindle organization Source: UniProtKB

Cellular Location

Centrosome; Spindle pole; Spindle; Kinetochore. Detected on centrosomes and kinetochores during interphase and mitosis independently from TACC3 and clathrin. Located to spindle poles and microtubules during mitosis. In complex with TACC3 localized to microtubule plus-ends in mitosis and interphase. In complex with TACC3 and clathrin localized to inter-microtubule bridges in mitotic spindles. Accumulation sites at microtubule plus ends protruded approximately 100 nm from MAPRE1/EB1 sites in interphase cells.