Human Nuclear Mitotic Apparatus Protein 1, NUMA1 ELI

Microtubule (MT)-binding protein that plays a role in the formation and maintenance of the spindle poles and the alignement and the segregation of chromosomes during mitotic cell division (PubMed: 7769006, PubMed: 17172455, PubMed: 19255246, PubMed: 24996901, PubMed: 26195665, PubMed: 27462074).

Functions to tether the minus ends of MTs at the spindle poles, which is critical for the establishment and maintenance of the spindle poles (PubMed: 12445386, PubMed: 11956313).

Plays a role in the establishment of the mitotic spindle orientation during metaphase and elongation during anaphase in a dynein-dynactin-dependent manner (PubMed: 23870127, PubMed: 24109598, PubMed: 24996901, PubMed: 26765568).

In metaphase, part of a ternary complex composed of GPSM2 and G(i) alpha proteins, that regulates the recruitment and anchorage of the dynein-dynactin complex in the mitotic cell cortex regions situated above the two spindle poles, and hence regulates the correct oritentation of the mitotic spindle (PubMed: 23027904, PubMed: 22327364, PubMed: 23921553).

During anaphase, mediates the recruitment and accumulation of the dynein-dynactin complex at the cell membrane of the polar cortical region through direct association with phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), and hence participates in the regulation of the spindle elongation and chromosome segregation (PubMed: 22327364, PubMed: 23921553, PubMed: 24996901, PubMed: 24371089).

Binds also to other polyanionic phosphoinositides, such as phosphatidylinositol 3-phosphate (PIP), lysophosphatidic acid (LPA) and phosphatidylinositol triphosphate (PIP3), in vitro (PubMed: 24996901, PubMed: 24371089).

Also required for proper orientation of the mitotic spindle during asymmetric cell divisions (PubMed: 21816348).

Plays a role in mitotic MT aster assembly (PubMed: 11163243, PubMed: 11229403, PubMed: 12445386).

Involved in anastral spindle assembly (PubMed: 25657325).

Positively regulates TNKS protein localization to spindle poles in mitosis (PubMed: 16076287).

Highly abundant component of the nuclear matrix where it may serve a non-mitotic structural role, occupies the majority of the nuclear volume (PubMed: 10075938).

Required for epidermal differentiation and hair follicle morphogenesis (By similarity).