KATNA1

Microtubules, polymers of alpha and beta tubulin subunits, form the mitotic spindle of a dividing cell and help to organize membranous organelles during interphase. Katanin is a heterodimer that consists of a 60 kDa ATPase (p60 subunit A 1) and an 80 kDa accessory protein (p80 subunit B 1). The p60 subunit acts to sever and disassemble microtubules, while the p80 subunit targets the enzyme to the centrosome. This gene encodes the p80 subunit. This protein is a member of the AAA family of ATPases. Multiple alternatively spliced variants, encoding the same protein, have been identified.

Full Name

Katanin Catalytic Subunit A1

Function

Catalytic subunit of a complex which severs microtubules in an ATP-dependent manner. Microtubule severing may promote rapid reorganization of cellular microtubule arrays and the release of microtubules from the centrosome following nucleation. Microtubule release from the mitotic spindle poles may allow depolymerization of the microtubule end proximal to the spindle pole, leading to poleward microtubule flux and poleward motion of chromosome. Microtubule release within the cell body of neurons may be required for their transport into neuronal processes by microtubule-dependent motor proteins. This transport is required for axonal growth.

Biological Process

Cell cycleIEA:UniProtKB-KW
Cell divisionIEA:UniProtKB-KW
Microtubule severingManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Cytoplasm; Midbody; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Cytoplasm, cytoskeleton, spindle pole; Cytoplasm, cytoskeleton, spindle. Predominantly cytoplasmic (PubMed:9658175).
Localized diffusely in the cytoplasm during the interphase (PubMed:10751153).
During metaphase is localized throughout the cell and more widely dispersed than the microtubules. In anaphase and telophase is localized at the midbody region (PubMed:19261606).
Also localized to the interphase centrosome and the mitotic spindle poles (By similarity).
Enhanced recruitment to the mitotic spindle poles requires microtubules and interaction with KATNB1 (PubMed:10751153).
Localizes within the cytoplasm, partially overlapping with microtubules, in interphase and to the mitotic spindle and spindle poles during mitosis (PubMed:26929214).

PTM

Phosphorylation by DYRK2 triggers ubiquitination and subsequent degradation.
Ubiquitinated by the BCR(KLHL42) E3 ubiquitin ligase complex, leading to its proteasomal degradation. Ubiquitinated by the EDVP E3 ligase complex and subsequently targeted for proteasomal degradation.