Kinesin-like protein KAR3

UniProtKB accession:  P17119

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Minus end-directed microtubule (MT) motor involved in spindle midzone assembly, poleward transport of newly captured kinetochores along the lateral side of MTs, karyogamy (nuclear fusion) during mating, and with an essential function in meiosis I (PubMed:11387196, PubMed:11729143, PubMed:17382884, PubMed:17620411, PubMed:22734002, PubMed:25313961, PubMed:7912193, PubMed:8106549, PubMed:9334348, PubMed:9859995). Functions together with the accessory proteins CIK1 or VIK1 (PubMed:10087265, PubMed:11729143, PubMed:15846338, PubMed:17382884, PubMed:22734002, PubMed:25313961). Drives the poleward transport of newly captured kinetochores along the lateral side of MTs, both during S-phase and during M-phase (PubMed:15846338, PubMed:17620411, PubMed:18079178). To contribute to spindle midzone assembly during mitotic metaphase, the nuclear KAR3-CIK1 motor cross-links anti-parallel microtubules to align them on the spindle axis; as the motor travels polewards splayed microtubules are pulled into alignment (PubMed:25313961). During the karyogamy (nuclear fusion) step of mating, KAR3-CIK1 cross-links antiparallel cytoplasmic microtubules emanating from the spindle pole bodies of mating partners; the motor activity of KAR3 creates the force that pulls the nuclei together by sliding cross-linked microtubules past one another (PubMed:2138512, PubMed:8106549). KAR3-CIK1 promotes microtubule shortening predominantly from the microtubule plus-end (PubMed:17382884). Together with cytoplasmic VIK1, may act to stabilize microtubules (PubMed:17382884). Requires accessory protein VIK1 for spindle pole body localization and to allow the CIN8 and KIP1 motors to generate outwardly directed spindle forces (PubMed:11729143, PubMed:2138512, PubMed:7912193, PubMed:8224825). Essential during meiosis I (PubMed:9334348). The ATPase activity is stimulated by microtubule-binding (PubMed:11387196, PubMed:22734002, PubMed:9859995).