| 生物功能 |
Component of the SKA complex, a microtubule plus end-binding complex of the outer kinetochore that stabilizes spindle microtubule-kinetochore attachments, promotes alignment of chromosomes at the mitotic spindle equator (chromosome congression) and assists suppression of the spindle assembly checkpoint (PubMed:17093495, PubMed:19289083, PubMed:22371557, PubMed:22483620, PubMed:23085020, PubMed:26981768, PubMed:27697923, PubMed:29487209, PubMed:31804178). Kinetochores, consisting of a centromere-associated inner segment and a microtubule-contacting outer segment, play a crucial role in chromosome segregation by mediating the physical connection between centromeric DNA and spindle microtubules (PubMed:19289083, PubMed:22483620, PubMed:23085020, PubMed:28479321, PubMed:29487209). The outer kinetochore is made up of the ten-subunit KMN network complex, comprising the MIS12, NDC80 and KNL1 complexes, and auxiliary microtubule-associated components such as the SKA complex; together they connect the outer kinetochore with the inner kinetochore, bind microtubules, and mediate interactions with mitotic checkpoint proteins that delay anaphase until chromosomes are bioriented on the spindle (PubMed:17093495, PubMed:19289083, PubMed:23085020, PubMed:28479321, PubMed:29487209). The SKA complex is loaded onto bioriented kinetochores and it facilitates chromosome congression by stabilizing microtubules together with MAPRE1, and end-on attachment of the NDC80 complex to depolymerizing spindle microtubules, thereby assisting the poleward-moving kinetochore in withstanding microtubule pulling forces (PubMed:19289083, PubMed:22371557, PubMed:22454517, PubMed:23085020, PubMed:24413531, PubMed:27697923, PubMed:28479321, PubMed:28495837, PubMed:29487209). The complex associates with dynamic microtubule plus-ends and can track both depolymerizing and elongating microtubules (PubMed:23085020, PubMed:29153323). The complex recruits protein phosphatase 1 (PP1) to the kinetochore in prometaphase and metaphase, to oppose spindle assembly checkpoint signaling and promote the onset of anaphase (PubMed:26981768). In the complex, it mediates interactions with microtubules (PubMed:19289083, PubMed:22483620, PubMed:23085020, PubMed:24413531, PubMed:27667719, PubMed:29153323, PubMed:36592928). It also stimulates AURKB/Aurora B catalytic activity (PubMed:27697923). During meiosis the SKA complex stabilizes the meiotic spindle and is required for its migration to the cortex (By similarity). [UniProt] |
