Substrate receptor subunit of a cullin-RING superfamily E3 ligase complex (CUL5-based E3 ubiquitin ligase complex) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins . Depending of the metabolic state of the cell, promotes the proteasomal degradation of IMPDH2, the rate-limiting enzyme in GTP biosynthesis or protects IMPDH2 by stabilizing IMPDH2 filaments assembly (, ). Implicated in different cellular processes, like copper homeostasis and cell proliferation (, ).
Subcellular locations: Cytoplasmic vesicle, Cytoplasm, Cytosol
Detected in long filamentous cytosolic structures where it colocalizes with IMPDH2 . Under basal conditions ANKRD9 is mainly in vesicle-like structures, upon nutrient limitation (guanine nucleotides deficiency) ANKRD9 loses its vesicular pattern and assembles with IMPDH2 into rodlike filaments .