Forms cell-cycle specific filaments between the spindle pole bodies of dividing yeast cells. Homooligomer; in vitro, FIN1 self-assembles into 10 nm diameter filaments. Interacts with the 14-3-3 proteins BMH1 and BMH2, and the protein phosphatase 1 complex catalytic subunit GLC7. Nuclear during early bud formation, located at the spindle poles during late mitosis, very low abundance in resting cells. Induced during G2-M transition. The coiled coil domain is essential for dimerization. Phosphorylated by CDC28. Phosphorylation is required for BMH1 and BMH2 interaction. Dephosphorylation by GLC7 depends on the presence of BMH1 and BMH2. Strong overexpression results in the accumulation of filamentous structures resembling the neurofibrillary tangles found in cells of patients with Alzheimer disease. Overexpression is lethal in haploids and causes very poor growth in diploids.