Kinesin Family, Member 18B (KIF18B)

KIF18B message of approximately 3kb is expressed in a tissue- and cell type-specific manners. A polypeptide of 842 amino acids was deduced from the ORF sequence. KIF18B is elevated at late G(2) through metaphase, very similar to cyclin B1. KIF18B protein is present predominantly in the nucleus and to a lesser extent in the cytoplasm of interphase cells. During mitosis, most KIF18B was found to be closely associated with astral microtubules emanating from the spindle pole during prometaphase and metaphase. KIF18B was not detected at anaphase and telophase, consistent with the Western blotting data. The nuclear localization signal was roughly determined by using several EGFP-tagged deletion mutants of KIF18B. KIF18B is regulated in a cell cycle-dependent manner and therefore may play an important role(s) in cell division.