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N-terminal domain (NTD) found in katanin p60 (Kp60) ATPase-containing subunit A1, and similar proteins This model represents the N-terminal domain (NTD) of katanin p60 ATPase-containing subunit A1 (also called p60 katanin 1 or katanin p60 subunit A1), which is organized into an antiparallel three-helix bundle and is responsible for tubulin binding. Katanin p60 subunit A1 plays a key role in cytoskeletal reorganization during various cellular events in an ATP-dependent manner. It is a microtubule-severing protein (MTSP) that maintains the density of spindle microtubules at the poles in mitotic cells. MSTPs are a group of microtubule-associated proteins essential for multiple microtubule-related processes, including mitosis and meiosis. 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 allows 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. Katanin p60 has been implicated in several malignancies; it is aberrantly expressed in prostate cancer patients with bone metastasis where upregulation of katanin P60 inhibits cell proliferation but enhances cell migration. It promotes cell migration in breast cancer where high ketanin p60 expression in tumor tissue is correlated with lymph node metastasis and poor overall survival. Katanin p60 may also be a potential biomarker for lymph node metastasis and prognosis for non-small cell lung cancer. Katanin is a heterodimer with an AAA catalytic subunit katanin P60 and a non-AAA subunit katanin P80. In ASPM (known as Asp in fly and ASPM-1 in worm), a microcephaly-associated protein family that regulates spindle architecture, the N-terminal domain of katanin p60 subunit (kp60-NTD) and C-terminal domain of katanin p80 subunit form a heterodimer, which then binds conserved motifs in ASPM, thus forming a complex that controls microtubule disassembly at spindle poles; misregulation of this process can lead to microcephaly. p60 katanin-like 1 has been shown to be predominantly enriched within oocytes and ovaries, and essential for oocyte meiosis and maturation. The N-terminal domain of mouse katanin p60 (kp60-NTD) also binds to tubulin; structure studies of kp60-NTD reveal a striking similarity to the microtubule interacting and trafficking (MIT) domains, although their sequence similarities are low. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",