Septin 2/6/7 complexes tune microtubule plus-end growth and EB1 binding in a concentration- and filament-dependent manner.

ABSTRACT: Septins (SEPTs) are filamentous guanosine-5'-triphosphate (GTP)-binding proteins, which affect microtubule (MT)-dependent functions including membrane trafficking and cell division, but their precise role in MT dynamics is poorly understood. Here, in vitro reconstitution of MT dynamics with SEPT2/6/7, the minimal subunits of septin heteromers, shows that SEPT2/6/7 has a biphasic concentration-dependent effect on MT growth. Lower concentrations of SEPT2/6/7 enhance MT plus-end growth and elongation, while higher and intermediate concentrations inhibit and pause plus-end growth, respectively. We show that SEPT2/6/7 has a modest preference for GTP- over guanosine diphosphate (GDP)-bound MT lattice and competes with end-binding protein 1 (EB1) for binding to guanosine 5'-O-[γ-thio]triphosphate

SUBMITTER: Nakos K 

PROVIDER: S-EPMC6822581 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature